From 1984 to 1988, 129 mitral valve reconstructions were done for primary pure mitral regurgitation. Sixty-two (48%) were done for myxomatous degeneration and prolapse of the mitral valve. Anterior leaflet resection was performed in seven patients, posterior leaflet resection in 46, anteroposterior resection in four; five patients received only a ring annuloplasty. Eight patients had coronary bypass grafts. Twenty-four patients received a Carpentier-Edwards annuloplasty ring, 24 a Duran ring, and 14 patients had no ring. Follow-up was 1 to 50 months (mean, 13 months). No patient was lost to follow-up. There was one operative death from gastrointestinal bleeding and two late deaths (one from suicide and one from a myocardial infarction), and the probability of survival at 48 months was 84% +/- 15%. There were no thromboembolic episodes or episodes of endocarditis. However, there were five reoperations (9%) with freedom from reoperation at 48 months of 85% +/- 5%. There was one major anticoagulant hemorrhage. Freedom from all morbidity at 48 months was 81% +/- 8%. Postoperative echocardiographic data in the three different groups of patients undergoing repair on the basis of annuloplasty treatment showed that the peak gradient was less and the valve area was slightly greater with no annuloplasty ring.