diff --git a/src/components/moderation/RejectionDialog.tsx b/src/components/moderation/RejectionDialog.tsx
new file mode 100644
index 00000000..953f1dfb
--- /dev/null
+++ b/src/components/moderation/RejectionDialog.tsx
@@ -0,0 +1,160 @@
+import { useState } from 'react';
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from '@/components/ui/dialog';
+import { Button } from '@/components/ui/button';
+import { Label } from '@/components/ui/label';
+import { Textarea } from '@/components/ui/textarea';
+import { RadioGroup, RadioGroupItem } from '@/components/ui/radio-group';
+import { AlertCircle } from 'lucide-react';
+
+export const REJECTION_REASONS = [
+  { value: 'incomplete', label: 'Incomplete Information', template: 'The submission is missing required information or details.' },
+  { value: 'inaccurate', label: 'Inaccurate Data', template: 'The information provided appears to be inaccurate or incorrect.' },
+  { value: 'duplicate', label: 'Duplicate Entry', template: 'This entry already exists in the database.' },
+  { value: 'inappropriate', label: 'Inappropriate Content', template: 'The submission contains inappropriate or irrelevant content.' },
+  { value: 'poor_quality', label: 'Poor Quality', template: 'The submission does not meet quality standards (e.g., blurry photos, unclear descriptions).' },
+  { value: 'spam', label: 'Spam', template: 'This appears to be spam or a test submission.' },
+  { value: 'custom', label: 'Other (Custom Reason)', template: '' },
+];
+
+interface RejectionDialogProps {
+  open: boolean;
+  onOpenChange: (open: boolean) => void;
+  itemCount: number;
+  hasDependents: boolean;
+  onReject: (reason: string, cascade: boolean) => void;
+}
+
+export function RejectionDialog({
+  open,
+  onOpenChange,
+  itemCount,
+  hasDependents,
+  onReject,
+}: RejectionDialogProps) {
+  const [selectedReason, setSelectedReason] = useState<string>('incomplete');
+  const [customReason, setCustomReason] = useState('');
+  const [cascade, setCascade] = useState(true);
+
+  const handleSubmit = () => {
+    const reasonTemplate = REJECTION_REASONS.find(r => r.value === selectedReason);
+    const finalReason = selectedReason === 'custom' 
+      ? customReason 
+      : reasonTemplate?.template || '';
+
+    if (!finalReason.trim()) {
+      return;
+    }
+
+    onReject(finalReason, cascade);
+    onOpenChange(false);
+    
+    // Reset state
+    setSelectedReason('incomplete');
+    setCustomReason('');
+    setCascade(true);
+  };
+
+  const currentReason = selectedReason === 'custom' ? customReason : 
+    REJECTION_REASONS.find(r => r.value === selectedReason)?.template || '';
+
+  return (
+    <Dialog open={open} onOpenChange={onOpenChange}>
+      <DialogContent className="max-w-2xl">
+        <DialogHeader>
+          <DialogTitle>Reject Submission Items</DialogTitle>
+          <DialogDescription>
+            You are about to reject {itemCount} item{itemCount !== 1 ? 's' : ''}. 
+            Please provide a reason for rejection.
+          </DialogDescription>
+        </DialogHeader>
+
+        <div className="space-y-4">
+          {hasDependents && (
+            <div className="flex items-start gap-2 p-4 bg-warning/10 border border-warning/20 rounded-lg">
+              <AlertCircle className="h-5 w-5 text-warning flex-shrink-0 mt-0.5" />
+              <div className="text-sm">
+                <p className="font-medium text-warning">Dependency Warning</p>
+                <p className="text-muted-foreground mt-1">
+                  Some selected items have dependent items. You can choose to cascade the rejection to all dependents.
+                </p>
+              </div>
+            </div>
+          )}
+
+          <div className="space-y-3">
+            <Label>Rejection Reason</Label>
+            <RadioGroup value={selectedReason} onValueChange={setSelectedReason}>
+              {REJECTION_REASONS.map((reason) => (
+                <div key={reason.value} className="flex items-start space-x-2">
+                  <RadioGroupItem value={reason.value} id={reason.value} className="mt-1" />
+                  <Label htmlFor={reason.value} className="font-normal cursor-pointer flex-1">
+                    <span className="font-medium">{reason.label}</span>
+                    {reason.template && (
+                      <p className="text-sm text-muted-foreground mt-0.5">{reason.template}</p>
+                    )}
+                  </Label>
+                </div>
+              ))}
+            </RadioGroup>
+          </div>
+
+          {selectedReason === 'custom' && (
+            <div className="space-y-2">
+              <Label htmlFor="custom-reason">Custom Reason *</Label>
+              <Textarea
+                id="custom-reason"
+                placeholder="Provide a detailed reason for rejection..."
+                value={customReason}
+                onChange={(e) => setCustomReason(e.target.value)}
+                rows={4}
+                className="resize-none"
+              />
+            </div>
+          )}
+
+          {hasDependents && (
+            <div className="space-y-2 pt-2 border-t">
+              <Label className="text-base">Dependency Handling</Label>
+              <RadioGroup value={cascade ? 'cascade' : 'orphan'} onValueChange={(v) => setCascade(v === 'cascade')}>
+                <div className="flex items-start space-x-2">
+                  <RadioGroupItem value="cascade" id="cascade" className="mt-1" />
+                  <Label htmlFor="cascade" className="font-normal cursor-pointer">
+                    <span className="font-medium">Cascade Rejection</span>
+                    <p className="text-sm text-muted-foreground">Reject all dependent items as well</p>
+                  </Label>
+                </div>
+                <div className="flex items-start space-x-2">
+                  <RadioGroupItem value="orphan" id="orphan" className="mt-1" />
+                  <Label htmlFor="orphan" className="font-normal cursor-pointer">
+                    <span className="font-medium">Keep Dependents Pending</span>
+                    <p className="text-sm text-muted-foreground">Leave dependent items in pending state</p>
+                  </Label>
+                </div>
+              </RadioGroup>
+            </div>
+          )}
+        </div>
+
+        <DialogFooter>
+          <Button variant="outline" onClick={() => onOpenChange(false)}>
+            Cancel
+          </Button>
+          <Button 
+            variant="destructive" 
+            onClick={handleSubmit}
+            disabled={!currentReason.trim()}
+          >
+            Reject {itemCount} Item{itemCount !== 1 ? 's' : ''}
+          </Button>
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  );
+}
diff --git a/src/components/moderation/SubmissionReviewManager.tsx b/src/components/moderation/SubmissionReviewManager.tsx
index 25c09477..ac8a7f0c 100644
--- a/src/components/moderation/SubmissionReviewManager.tsx
+++ b/src/components/moderation/SubmissionReviewManager.tsx
@@ -7,6 +7,7 @@ import {
   buildDependencyTree, 
   detectDependencyConflicts,
   approveSubmissionItems,
+  rejectSubmissionItems,
   escalateSubmission,
   type SubmissionItemWithDeps,
   type DependencyConflict 
@@ -25,6 +26,7 @@ import { ItemReviewCard } from './ItemReviewCard';
 import { DependencyVisualizer } from './DependencyVisualizer';
 import { ConflictResolutionDialog } from './ConflictResolutionDialog';
 import { EscalationDialog } from './EscalationDialog';
+import { RejectionDialog } from './RejectionDialog';
 
 interface SubmissionReviewManagerProps {
   submissionId: string;
@@ -45,6 +47,7 @@ export function SubmissionReviewManager({
   const [loading, setLoading] = useState(false);
   const [showConflictDialog, setShowConflictDialog] = useState(false);
   const [showEscalationDialog, setShowEscalationDialog] = useState(false);
+  const [showRejectionDialog, setShowRejectionDialog] = useState(false);
   const [activeTab, setActiveTab] = useState<'items' | 'dependencies'>('items');
   
   const { toast } = useToast();
@@ -151,20 +154,53 @@ export function SubmissionReviewManager({
   };
 
   const handleRejectSelected = async () => {
+    if (selectedItemIds.size === 0) {
+      toast({
+        title: 'No Items Selected',
+        description: 'Please select items to reject',
+        variant: 'destructive',
+      });
+      return;
+    }
+
+    if (!user?.id) {
+      toast({
+        title: 'Authentication Required',
+        description: 'You must be logged in to reject items',
+        variant: 'destructive',
+      });
+      return;
+    }
+
+    // Check if any selected items have dependents
+    const selectedItems = items.filter(item => selectedItemIds.has(item.id));
+    const hasDependents = selectedItems.some(item => 
+      item.dependents && item.dependents.length > 0
+    );
+
+    setShowRejectionDialog(true);
+  };
+
+  const handleReject = async (reason: string, cascade: boolean) => {
+    if (!user?.id) return;
+
     setLoading(true);
     try {
-      // TODO: Implement rejection with reason
-      toast({
-        title: 'Success',
-        description: `Rejected ${selectedItemIds.size} item(s)`,
-      });
+      const selectedItems = items.filter(item => selectedItemIds.has(item.id));
+      await rejectSubmissionItems(selectedItems, reason, user.id, cascade);
       
+      toast({
+        title: 'Items Rejected',
+        description: `Successfully rejected ${selectedItems.length} item${selectedItems.length !== 1 ? 's' : ''}`,
+      });
+
       onComplete();
       onOpenChange(false);
     } catch (error: any) {
+      console.error('Error rejecting items:', error);
       toast({
         title: 'Error',
-        description: error.message || 'Failed to reject items',
+        description: 'Failed to reject items. Please try again.',
         variant: 'destructive',
       });
     } finally {
@@ -246,6 +282,16 @@ export function SubmissionReviewManager({
         onOpenChange={setShowEscalationDialog}
         onEscalate={handleEscalate}
       />
+
+      <RejectionDialog
+        open={showRejectionDialog}
+        onOpenChange={setShowRejectionDialog}
+        itemCount={selectedItemIds.size}
+        hasDependents={items.filter(item => selectedItemIds.has(item.id)).some(item => 
+          item.dependents && item.dependents.length > 0
+        )}
+        onReject={handleReject}
+      />
     </>
   );
 
diff --git a/src/lib/submissionItemsService.ts b/src/lib/submissionItemsService.ts
index 73efdaec..d75a7aa6 100644
--- a/src/lib/submissionItemsService.ts
+++ b/src/lib/submissionItemsService.ts
@@ -281,6 +281,113 @@ async function approvePhotos(data: any): Promise<string> {
   return data.photos?.[0]?.url || '';
 }
 
+/**
+ * Reject multiple items with optional cascade to dependents
+ */
+export async function rejectSubmissionItems(
+  items: SubmissionItemWithDeps[],
+  reason: string,
+  userId: string,
+  cascade: boolean = true
+): Promise<void> {
+  if (!userId) {
+    throw new Error('User authentication required to reject items');
+  }
+
+  if (!reason || !reason.trim()) {
+    throw new Error('Rejection reason is required');
+  }
+
+  const itemsToReject = new Set<string>(items.map(i => i.id));
+
+  // If cascading, collect all dependent items
+  if (cascade) {
+    for (const item of items) {
+      await collectDependents(item, itemsToReject);
+    }
+  }
+
+  // Update all items to rejected status
+  const updates = Array.from(itemsToReject).map(async (itemId) => {
+    const { error } = await supabase
+      .from('submission_items')
+      .update({
+        status: 'rejected',
+        rejection_reason: reason,
+        updated_at: new Date().toISOString(),
+      })
+      .eq('id', itemId);
+
+    if (error) {
+      console.error(`Error rejecting item ${itemId}:`, error);
+      throw error;
+    }
+  });
+
+  await Promise.all(updates);
+
+  // Update parent submission status
+  const submissionId = items[0]?.submission_id;
+  if (submissionId) {
+    await updateSubmissionStatusAfterRejection(submissionId);
+  }
+}
+
+async function collectDependents(
+  item: SubmissionItemWithDeps,
+  rejectedSet: Set<string>
+): Promise<void> {
+  if (item.dependents && item.dependents.length > 0) {
+    for (const dependent of item.dependents) {
+      rejectedSet.add(dependent.id);
+      await collectDependents(dependent, rejectedSet);
+    }
+  }
+}
+
+async function updateSubmissionStatusAfterRejection(submissionId: string): Promise<void> {
+  // Get all items for this submission
+  const { data: allItems, error: fetchError } = await supabase
+    .from('submission_items')
+    .select('status')
+    .eq('submission_id', submissionId);
+
+  if (fetchError) {
+    console.error('Error fetching submission items:', fetchError);
+    return;
+  }
+
+  if (!allItems || allItems.length === 0) return;
+
+  const statuses = allItems.map(i => i.status);
+  const allRejected = statuses.every(s => s === 'rejected');
+  const allApproved = statuses.every(s => s === 'approved');
+  const anyPending = statuses.some(s => s === 'pending');
+
+  let newStatus: string;
+  if (allRejected) {
+    newStatus = 'rejected';
+  } else if (allApproved) {
+    newStatus = 'approved';
+  } else if (anyPending) {
+    newStatus = 'pending';
+  } else {
+    newStatus = 'partially_approved';
+  }
+
+  const { error: updateError } = await supabase
+    .from('content_submissions')
+    .update({
+      status: newStatus,
+      updated_at: new Date().toISOString(),
+    })
+    .eq('id', submissionId);
+
+  if (updateError) {
+    console.error('Error updating submission status:', updateError);
+  }
+}
+
 /**
  * Escalate submission for admin review
  */