Limited information is available concerning the long-term survival of patients with atrioventricular discordance, ventriculoarterial discordance, and two ventricles (corrected transposition). The long-term follow-up of 107 patients examined at the Mayo Clinic over a 30-year period between 1951 and 1981 was reviewed. Overall survival from the date of Mayo Clinic diagnosis was 70% at five years and 64% at ten years. Associated variables were analyzed for their effect on survival including sex, age at diagnosis, presence of ventricular septal defect, pulmonary stenosis, dextrocardia, left atrioventricular valve insufficiency, and complete heart block. There was no significant difference between those with and without a ventricular septal defect (VSD). Pulmonary stenosis was protective when a VSD was present but was not a significant predictor of long-term survival. The only variable that consistently correlated with decreased survival was left atrioventricular valve insufficiency (p less than 0.04 for univariate and stepwise Cox, and p = 0.08 for multivariate analysis). A logistic model for survival after open-heart surgery failed to identify any significant variable. We conclude that the presence of left atrioventricular valve insufficiency in association with atrioventricular discordance significantly alters the long-term outcome. Atrioventricular valve replacement should be considered in such patients when insufficiency becomes hemodynamically significant.