OBJECTIVE: Congenital aortopulmonary window is rare, often associated with other cardiac anomalies. Surgical repair as the only treatment should be performed before pulmonary vascular changes have developed. This study presents the long-term outcome after surgical correction for this condition. MATERIALS AND METHODS: Between 1971 and 1993, 13 patients with congenital aortopulmonary window were found. 10 had type I, 2 type II and 1 had type III. Concomitant cardiac anomalies were present in 10/13. Eleven patients were operated on at a mean age of 31.2 +/- 48.3 months (range 6 days-10 years). Thoracotomy was used in 3 and sternotomy in 9 patients. In 4/11, the aorto-pulmonary window was simply ligated, 4 had a transpulmonary approach and 1 combined with a transaortic approach. The aortopulmonary window was closed directly in 2 and with a Dacron patch in 1. Cardiopulmonary bypass was used in 6 patients. Associated anomalies in 10/11 patients. RESULTS: There was one operative death (9%): a six-day old boy with interrupted aortic arch died 6 h postoperatively due to low-cardiac output. The mean follow-up period is 8.1 +/- 7.3 years (range 2-24 years). Clinical examination, transaortic echocardiography and/or cardiac catheterization were obtained in the follow-up. There was no late death. All are in New York Heart Association (NYHA) class I. One had to be reoperated on for a recurrent shunt 29 months after ligation and one had angioplasty after 23 months for residual stenosis of the reimplanted right pulmonary artery. The actuarial survival rate is 90% after 1, 5 and 10 years. CONCLUSIONS: The surgical treatment of aortopulmonary window has a low risk, even if associated with major cardiac anomalies. Prompt operative treatment achieves excellent long-term results.