One hundred and fifty-five patients with isolated mitral regurgitation were referred from our cardiology department for mitral valve repair between 1972 and 1990. Men were predominant (59%), mean age was 51 years, and 61% of the patients were in NYHA class III or IV. Degenerative aetiology was predominant (65%). Surgical repair was performed according to the Carpentier techniques. Two operative deaths occurred (1.3%). The survivors were followed-up for an average of 4 years, and the rates of survival and good functional results at 11.5 years, were respectively 84.5% and 64.5%. The linearized rates of endocarditis, thromboembolic events and re-operations were respectively 0.35%, 1.54% and 2.05% pt-yrs. Residual mitral regurgitation was looked for by clinical and Doppler examination: there was no regurgitation in 55.5% of patients, mild regurgitation was found in 26%, moderate in 10.3% and severe in 8.2%. Analysis of moderate and severe residual regurgitation identified three promoting factors: rheumatic origin of the regurgitation, surgery of the anterior leaflet and time of surgery (the incidence after surgery has been lower in recent years). Other 'less well known' complications were encountered: left ventricular outflow tract obstruction, progressive evolution towards mitral stenosis, appearance of aortic regurgitation and formation of left atrial thrombi. Despite these complications, we must stress the satisfactory results of the technique, in particular in mitral valve endocarditis; 22 patients were operated on for this reason, six during the acute phase of the disease, and no surgical death, or recurrence of endocarditis, and only one case of severe residual regurgitation was observed.