Controversy remains regarding whether valve repair is preferable to valve replacement in children suffering from rheumatic mitral valve disease. To answer this question, 130 children aged 3 to 15 years (mean age, 11.8 +/- 2.8 years) undergoing surgery between January 1992 and December 1997 using Carpentier's techniques were reviewed. There were 111 cases of rheumatic valve diseases (85%), 17 cases of congenital mitral valve malformations (13%), one case of Barlow's syndrome (1%), and one case of bacterial endocarditis (1%). Valve dysfunction was classified into three types according to Carpentier's classification. There were 14 type II (leaflet prolapse), 78 type III (restricted leaflet motion), and 38 associated type II (anterior leaflet) and III (posterior leaflet) cases. There was one early (in-hospital) death (0.7%); the remaining 129 children were examined every 6 months. At the last examination, 99.2% of the patients were still alive, 96.8% were free of reoperation, and 89% showed no sign of significant residual stenosis or insufficiency on echocardiography. There have been no thromboembolisms. We conclude that mitral valve repair using Carpentier's techniques is the preferred procedure in the surgical treatment of mitral valve incompetence in children, even in those with rheumatic valvular disease. Copyright 1999 by W.B. Saunders Company