Twenty-five patients with ventricular septal defect (VSD) associated with aortic insufficiency (AI) have been since 1964. Of these patients, one died suddenly without operation; in 2 patients, AI developed in the late postoperative period following VSD closure; and in 3 others, AI developed shortly after VSD closure. The remaining 19 patients are discussed in detail. The VSD was subpulmonic in 13 (68 per cent) and subcristal in 6 (32 per cent). Primary suture of the VSD was undertaken in 13 patients and patch closure in 6. Seven patients had aortic valvuloplasty and 2 had aortic valve replacement. There were no surgical deaths, and the long-term follow-up shows that VSD closure alone has been sufficient to arrest progression of AI in patients with mild insufficiency, particularly in those with subpulmonic VSD. Valvuloplasty, when necessary, was more effective when done at an early age.