diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/SparkStrategies.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/SparkStrategies.scala
index 5efad83bcba78..154a58309cff7 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/SparkStrategies.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/SparkStrategies.scala
@@ -328,7 +328,8 @@ abstract class SparkStrategies extends QueryPlanner[SparkPlan] {
             .getOrElse(createJoinWithoutHint())
         }
 
-      case j @ ExtractSingleColumnNullAwareAntiJoin(leftKeys, rightKeys) =>
+      case j @ ExtractSingleColumnNullAwareAntiJoin(leftKeys, rightKeys)
+          if canBroadcastBySize(j.right, conf) =>
         Seq(joins.BroadcastHashJoinExec(leftKeys, rightKeys, LeftAnti, BuildRight,
           None, planLater(j.left), planLater(j.right), isNullAwareAntiJoin = true))
 
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/JoinSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/JoinSuite.scala
index 885512d4d1980..b5393cec451a0 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/JoinSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/JoinSuite.scala
@@ -1271,6 +1271,22 @@ class JoinSuite extends QueryTest with SharedSparkSession with AdaptiveSparkPlan
     }
   }
 
+  test("SPARK-45846: optimizeNullAwareAntiJoin should respect autoBroadcastJoinThreshold") {
+    withSQLConf(SQLConf.OPTIMIZE_NULL_AWARE_ANTI_JOIN.key -> "true",
+      SQLConf.AUTO_BROADCASTJOIN_THRESHOLD.key -> "-1") {
+      // When broadcast is disabled, null-aware anti-join should not use BroadcastHashJoinExec
+      val df = sql("select * from testData where key not in (select a from testData2)")
+      val physical = df.queryExecution.sparkPlan
+      // Collect all BroadcastHashJoinExec nodes
+      val broadcastHashJoins = collect(physical) {
+        case j: BroadcastHashJoinExec => j
+      }
+      // Verify no BroadcastHashJoinExec with isNullAwareAntiJoin is used
+      assert(broadcastHashJoins.forall(!_.isNullAwareAntiJoin),
+        "Null-aware anti-join should not use BroadcastHashJoinExec when broadcast is disabled")
+    }
+  }
+
   test("SPARK-32399: Full outer shuffled hash join") {
     val inputDFs = Seq(
       // Test unique join key