From January 1991 through December 2001, 600 patients underwent closure of a perimembranous ventricular septal defect through a right atrial approach at our institution. In 122 of these patients, the operation included temporary detachment of a tricuspid valve septal leaflet from the annulus to allow complete visualization of a perimembranous ventricular septal defect The mean age of the patients at surgery was 4.6 years in those who underwent leaflet detachment and 4.7 years in the 478 patients who did not (P > 0.05). Preoperatively, all patients were in sinus rhythm. Echocardiography showed trivial tricuspid regurgitation in 21 of the patients undergoing detachment and in 39 of the non-detachment patients. There was no difference in bypass time or aortic cross-clamp time between the 2 groups. Postoperatively, 3 patients in the non-detachment group had heart block; all other patients were in sinus rhythm. Echocardiograms on the 7th postoperative day showed small residual ventricular septal defects in none of the patients who underwent valve detachment and in 10 of the non-detachment patients; mild tricuspid regurgitation was present in 12 non-detachment patients only; and trivial tricuspid regurgitation was present in 19 patients who underwent valve detachment and in 29 who did not. There was no hospital death in either group. Long-term follow-up showed no progression of tricuspid regurgitation or tricuspid stenosis. All patients remained in sinus rhythm. This study suggests that tricuspid valve detachment is a safe, effective technique that improves exposure for ventricular septal defect repair and does not adversely affect valve competence.