BackgroundRare as membranous ventricular septal aneurysms (MVSA) is, the possibility that occurs after ventricular septum defect (VSD) repair surgery is even more uncommon.PresentationA girl developed a MVSA 3 years after the VSD repair surgery at the age of 1 and increasing growth was noted during the follow-up. Aneurysm plication was carried done when she was 11 years old because it was observed to have a close relationship to the right coronary and obstructed the right ventricular outflow tract. Postoperative echocardiography follow-up revealed no abnormalities.ConclusionThough the prognosis of most patients with VSD repaired surgery was good, there remains varieties type of complications despite surgical advances. Accurate and rapid diagnosis of acute and delayed complications is essential to improve prognosis. In this case, the aneurysm was diagnosed by multiple imaging modalities and the girl underwent successful surgery again which provides direction for awareness and knowledge of delayed complications of VSD repair.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12872-023-03361-1.