OBJECTIVE The study aim was to assess the long-term durability of mitral valve (MV) repair for MV prolapse using echo-Doppler evaluation. METHODS Between July 1991 and December 2006, MV repair was performed in 603 patients with nonischemic, severe mitral regurgitation (MR). A subset of 517 patients (mean age 56.3 +/- 12.0 years) with MR caused by leaflet prolapse resulting from degeneration of the MV was subsequently investigated. The main techniques used for MV repair included chordal replacement with ePTFE sutures for 274 of 278 patients with anterior leaflet (AL) prolapse, and leaflet resection for 239 patients with posterior leaflet (PL) prolapse. A prosthetic ring or band was used for annuloplasty in 340 patients, and a band of autologous pericardium in 161; no ring or band was used in the remaining 16 cases. Postoperative serial transthoracic echocardiography was performed for all hospital survivors before discharge, and on at least one occasion after discharge in 507 patients. Echocardiographic follow up was available for up to 15 years (mean 4.4 +/- 3.6 years). Residual MR flow detected by color Doppler echocardiography was classified according to the maximum regurgitant jet area (MRA). RESULTS The 30-day mortality was 0.57% (three deaths). There were 21 late deaths and 22 reoperations (five of which were re-repair for hemolysis). Kaplan-Meier survival and freedom from reoperation at 14 years were 79.0 +/- 6.0% and 74.5 +/- 9.6%, respectively. Estimates of freedom from severe MR (MRA > or = 7.0 cm2) at five, 10 and 14 years were 94.2 +/- 1.5%, 82.8 +/- 3.6% and 77.5 +/- 5.5%, respectively. Freedom from severe MR at 14 years for 239 patients with isolated PL prolapse was 98.4 +/- 1.6%. CONCLUSIONS Echocardiographic follow up of MV repair for MV prolapse demonstrates good long-term results. In particular, the results of MV repair for isolated PL prolapse were excellent.