Although mitral valve repair is a recognized method to surgically treat mitral valve regurgitation, the ideal timing of the operation still is controversial. The goal of this study was to study the long-term results of mitral valve repair focusing on symptomatic versus nonsymptomatic patients. From October 1988 to June 1994, 262 patients (mean age = 57.4) with isolated mitral regurgitation underwent mitral valve repair. Seventy-nine patients (group I) were nonsymptomatic (NYHA Class I or II) and 184 (group II) were severely symptomatic (NYHA III or IV). The surgical techniques have been mainly those described by Alain Carpentier. All patients but three had an annuloplasty with a Carpentier ring. Mean follow-up was 4.02 +/- 0.1 years and total follow-up, 972 patient-years. There was one operative death (0.4%). Postoperative Doppler echocardiography showed satisfactory mitral valve function in 97% of the patients and two eases of systolic systolic anterior motion (1%). At 7 years, actuarial survival was 80% +/- 9%, 95% +/- 5%, 75% +/-11% for the total group, group I, and group II, respectively. At 7 years, freedom from thromboembolic or bleeding complications and reoperation was 96% +/- 4%, 93% +/- 8%, and 94% +/- 3%, respectively. Mitral valve repair for isolated mitral valve regurgitation provides satisfactory survival at 7 years. The long-term survival is better when patients are operated at an early stage when they are still nonsymptomatic.