Rupture of congenital sinus of Valsalva aneurysm is a rare cardiac malformation that usually causes reduced cardiac performance. Twenty patients (mean age 28.3 ± 10.7 years; range: 14 to 55 years) with this condition were operated on between January 1985 and March 1999. The ruptured aneurysms originated in the right coronary sinus in 18 patients (90%) and the non-coronary sinus in two (10%). No ruptures originated from the left coronary sinus. Aneurysms ruptured into the right ventricle in 14 patients (70%), the right atrium in five (25%), and the left ventricle in one patient (5%). Subarterial ventricular septal defect (VSD) (30%) and aortic insufficiency (20%) were common associated defects. No correlation was found between subarterial VSDs and aortic insufficiency (p >0.05). For repair, the aorta and cavity into which the aneurysm had ruptured were opened. The aneurysmal sac was excised and the defect closed with (n = 18) or without (n = 2) a patch. The in-hospital mortality rate was 5% (n = 1); no late mortality was observed. Patients were followed up for 4.4 ± 3.3 years (range: 1 to 13 years). The actuarial survival rate was 95% at 12.35 years. Recurrence of fistula occurred in one patient (5%) in whom the rupture was closed without a patch. At 12.3 years, actuarial freedom from recurrence of fistula was 94.74% for all survivors, and 100% for patients with patch closure. Probability of freedom from reoperation for recurrence was 100%. No late complications were observed. To conclude, surgical repair is the treatment of choice for ruptured sinus of Valsalva aneurysm. Surgery performed rapidly after diagnosis leads to an excellent outcome.