diff --git a/posthog/api/feature_flag.py b/posthog/api/feature_flag.py
index b1d7f433422c3..764e8b1c78638 100644
--- a/posthog/api/feature_flag.py
+++ b/posthog/api/feature_flag.py
@@ -394,6 +394,12 @@ def validate_filters(self, filters):
             # mypy cannot tell that self.instance is a FeatureFlag
             return self.instance.filters
 
+        groups = filters.get("groups", [])
+        if isinstance(groups, list) and len(groups) == 0:
+            raise serializers.ValidationError(
+                "Feature flag filters must contain at least one condition set. Empty 'groups' array is not allowed."
+            )
+
         aggregation_group_type_index = filters.get("aggregation_group_type_index", None)
 
         def properties_all_match(predicate):