Between January 1984 and December 1994, 130 patients underwent mitral valvuloplasty for pure dystrophic mitral regurgitation. There were 94 men and 36 women with a mean age of 61 +/- 9 years: 52 patients were in atrial fibrillation; 91% of patients were in NYHA Classes III or IV. At preoperative echocardiography, the regurgitation was assessed as Grade III or IV and classified using the Carpentier classification according to type I (dilatation of the annulus) or II (mitral valve prolapse); 95% of patients had isolated prolapse of the posterior leaflet, 3% had isolated prolapse of the anterior leaflet and 2% had prolapse of the two leaflets. After valvuloplasty, a prosthetic ring was implanted in 124 patients (95%). The early mortality was 3%; 5.3% of patients had early complications. All patients underwent control transthoracic echocardiography in the first postoperative week. They were reviewed with a second transthoracic echocardiography after a mean follow-up of 5 +/- 0.3 years and a cumulative follow-up of 657 years-patients. At the immediate postoperative echocardiography, 24 minimal residual regurgitations were observed; at long-term, 20 new mitral regurgitations developed, all mild without any clinical symptoms and 98% of patients were in the NYHA Classes I or II. At 10 years, the actuarial survival was 73 +/- 16%; absence of thromboembolic complications 95 +/- 3%, absence of reoperation 95 +/- 5%. This study confirms the efficacy of mitral valvuloplasty and the postoperative stability of repaired valvular lesions. These results suggest that the operative indications should be considered at an earlier stage.