diff --git a/pkg/crosscluster/logical/txnlock/lock_synthesis_test.go b/pkg/crosscluster/logical/txnlock/lock_synthesis_test.go
index e0757c46f2b4..7b57c8f08f54 100644
--- a/pkg/crosscluster/logical/txnlock/lock_synthesis_test.go
+++ b/pkg/crosscluster/logical/txnlock/lock_synthesis_test.go
@@ -191,6 +191,12 @@ func selfRefRow(id, parentID, data int) tree.Datums {
 	}
 }
 
+// pkFKRow builds datums for schemas (id INT PRIMARY KEY) and
+// (id INT PRIMARY KEY REFERENCES pk_fk_parent(id)).
+func pkFKRow(id int) tree.Datums {
+	return tree.Datums{tree.NewDInt(tree.DInt(id))}
+}
+
 // compositeFKParentRow builds datums for schema
 // (a INT, b INT, c INT, d INT, val INT, PRIMARY KEY (a, b), UNIQUE (c, d)).
 func compositeFKParentRow(a, b, c, d, val int) tree.Datums {
@@ -249,6 +255,11 @@ func TestDeriveLocks(t *testing.T) {
 			parent_id INT REFERENCES fk_self_ref(id),
 			data INT
 		)`)
+	runner.Exec(t, `CREATE TABLE pk_fk_parent (id INT PRIMARY KEY)`)
+	runner.Exec(t, `
+		CREATE TABLE pk_fk_child (
+			id INT PRIMARY KEY REFERENCES pk_fk_parent(id)
+		)`)
 	runner.Exec(t, `
 		CREATE TABLE composite_fk_parent (
 			a INT, b INT, c INT, d INT, val INT,
@@ -279,6 +290,12 @@ func TestDeriveLocks(t *testing.T) {
 	selfRefDesc := cdctest.GetHydratedTableDescriptor(
 		t, s.ExecutorConfig(), "fk_self_ref",
 	)
+	pkFKParentDesc := cdctest.GetHydratedTableDescriptor(
+		t, s.ExecutorConfig(), "pk_fk_parent",
+	)
+	pkFKChildDesc := cdctest.GetHydratedTableDescriptor(
+		t, s.ExecutorConfig(), "pk_fk_child",
+	)
 	compositeFKParentDesc := cdctest.GetHydratedTableDescriptor(
 		t, s.ExecutorConfig(), "composite_fk_parent",
 	)
@@ -292,6 +309,8 @@ func TestDeriveLocks(t *testing.T) {
 	parentEB := ldrdecoder.NewTestEventBuilder(t, parentDesc.TableDesc())
 	childEB := ldrdecoder.NewTestEventBuilder(t, childDesc.TableDesc())
 	selfRefEB := ldrdecoder.NewTestEventBuilder(t, selfRefDesc.TableDesc())
+	pkFKParentEB := ldrdecoder.NewTestEventBuilder(t, pkFKParentDesc.TableDesc())
+	pkFKChildEB := ldrdecoder.NewTestEventBuilder(t, pkFKChildDesc.TableDesc())
 	compositeFKParentEB := ldrdecoder.NewTestEventBuilder(t, compositeFKParentDesc.TableDesc())
 	compositeChildEB := ldrdecoder.NewTestEventBuilder(t, compositeChildDesc.TableDesc())
 	txnTime := s.Clock().Now()
@@ -305,6 +324,8 @@ func TestDeriveLocks(t *testing.T) {
 			{SourceDescriptor: parentDesc, DestID: parentDesc.GetID()},
 			{SourceDescriptor: childDesc, DestID: childDesc.GetID()},
 			{SourceDescriptor: selfRefDesc, DestID: selfRefDesc.GetID()},
+			{SourceDescriptor: pkFKParentDesc, DestID: pkFKParentDesc.GetID()},
+			{SourceDescriptor: pkFKChildDesc, DestID: pkFKChildDesc.GetID()},
 			{SourceDescriptor: compositeFKParentDesc, DestID: compositeFKParentDesc.GetID()},
 			{SourceDescriptor: compositeChildDesc, DestID: compositeChildDesc.GetID()},
 		},
@@ -323,6 +344,8 @@ func TestDeriveLocks(t *testing.T) {
 			{DestID: parentDesc.GetID()},
 			{DestID: childDesc.GetID()},
 			{DestID: selfRefDesc.GetID()},
+			{DestID: pkFKParentDesc.GetID()},
+			{DestID: pkFKChildDesc.GetID()},
 			{DestID: compositeFKParentDesc.GetID()},
 			{DestID: compositeChildDesc.GetID()},
 		},
@@ -824,6 +847,28 @@ func TestDeriveLocks(t *testing.T) {
 				order:          []int{1, 0},
 			},
 		},
+		{
+			// Deleting a child and its parent where the child's FK column is
+			// also its primary key.
+			//
+			// This test is a regression test for the following behavior (#169778):
+			//	1. We always emit the PK for a deleted row.
+			//	2. It's possible for a FK (but not a UC) to decode as
+			//	   the same exact value as its own PK.
+			// Deleting such a row would appear as though the fk was updated
+			// rather than deleted if we only checked the row values, instead
+			// of the actual decoded row IsDelete. This would cause this test
+			// to errornously detect a cycle.
+			name: "fk_delete_child_then_parent_pk_fk",
+			txn1: txnCase{
+				events: []streampb.StreamEvent_KV{
+					pkFKParentEB.DeleteEvent(txnTime, pkFKRow(1)),
+					pkFKChildEB.DeleteEvent(txnTime, pkFKRow(1)),
+				},
+				writeLockCount: 3,
+				order:          []int{1, 0},
+			},
+		},
 		{
 			// Inserting a new parent and a child that references it in the
 			// same txn. The parent must be inserted before the child so the
diff --git a/pkg/crosscluster/logical/txnlock/schema.go b/pkg/crosscluster/logical/txnlock/schema.go
index b8140b87043b..b0ad84d0530e 100644
--- a/pkg/crosscluster/logical/txnlock/schema.go
+++ b/pkg/crosscluster/logical/txnlock/schema.go
@@ -310,17 +310,19 @@ func (t *tableConstraints) fkDependsOn(
 ) (bool, error) {
 	// a is the child, b is the parent. a depends on b if b is inserting a
 	// parent value that a's new row needs to reference.
-	for _, outbound := range t.OutboundForeignKeyConstraints {
-		inbound, ok := otherTC.InboundForeignKeyConstraints[outbound.mixin]
-		if !ok {
-			continue
-		}
-		eq, err := columnSetEqual(ctx, t.evalCtx, &outbound, &inbound, a.Row, b.Row)
-		if err != nil {
-			return false, err
-		}
-		if eq {
-			return true, nil
+	if !a.IsDelete && !b.IsDelete {
+		for _, outbound := range t.OutboundForeignKeyConstraints {
+			inbound, ok := otherTC.InboundForeignKeyConstraints[outbound.mixin]
+			if !ok {
+				continue
+			}
+			eq, err := columnSetEqual(ctx, t.evalCtx, &outbound, &inbound, a.Row, b.Row)
+			if err != nil {
+				return false, err
+			}
+			if eq {
+				return true, nil
+			}
 		}
 	}