From January 1980 to December 1989, thirteen patients underwent operation for ventricular septal defect associated with aortic insufficiency in Kyungpook national university hospital. Ten male and three female patients ranged in age from 3 years to 25 years, with an average age of 11.5 years. Aortic cusp prolapse was found in eight cases[61.5%]. The aortic regurgitation was classified by Sellers` method with grade I in 2 cases, grade II in 9 cases, and grade III in 2 cases. Direct suture or patch repair of ventricular septal defect was performed through the right ventricle. Eight cases were treated only by closure of VSD, 3 cases by plication, but two of the letter were reoperated due to the persistent of aortic regurgitation and fungal endocarditis respectively. Aortic valve replacement were performed in 2 cases at the first operation. There was only one late death[7.7%], which was caused by postoperative fungal endocarditis. Follow-up for twelve patients except one death were followed up for 3 months to six years after operation. Residual aortic regurgitation was noted in six cases[46.2%], but the postoperative course of them were uneventful.