Thirty-two children with both ventricular septal defect (VSD) and aortic insufficiency (AI) were evaluated for progression in degree of AI as well as effectiveness of operation in reducing or eliminating regurgitation. At the time of initial study. AI was mild in 21, moderate in eight, and severe in three patients. Twenty-one patients were followed medically over a 2 year to 19 year period, during which the degree of AI progressed in five. One death occurred during an episode of endocarditis. A total of 24 patients underwent operation at ages ranging from 1 year to 23 years. Postoperative evaluations continued from a minimum of 1 year to 24 years in 19 patients, with residual AI noted in 63% of these. Children less than 5 years of age, even with little valvular involvement, exhibited minimal benefit from attempted correction compared with those in the latter part of the first decade of life (p less than 0.05). Closure of the VSD with associated valvuloplasty resulted in a higher prevalence of elimination or improvement of AI compared with VSD closure alone (p less than 0.01). As AI can progress slowly without compromising the child's development, attempted surgical repair can safely be deferred in children less than 5 years of age with minimal valvular involvement unless careful medical management fails to prevent cardiac decompensation.