Mitral balloon valvulotomy has proven to be an effective method for the treatment of patients with mitral stenosis. Although several factors determining an optimal immediate result have been described, there is few information regarding the longterm follow-up as well as factors influencing late success after the procedure. In this article, we analyzed our series of 311 patients treated by mitral balloon valvulotomy who were clinically followed between 3 months and 5 years (mean 23 +/- 11 months). At least, one echo-Doppler follow-up study was obtained in 260 patients, 20 +/- 10 months after. Hemodynamic re-evaluations were performed in 63 patients after 20 +/- 11 months. Late success was defined as the patient being in functional class I-II and free of major events (death, restenosis or valve surgery). Restenosis was defined as the loss of 50% of initial gain in terms of valve area, confirmed always hemodynamically. Major events during follow-up period occurred in 19 patients (10 deaths, 8 restenosis and 11 mitral valve surgery). We performed a multivariate study using the Cox-regression model. In the analysis, all variables with or near statistic significance in the univariate analysis (Mantel-Haezel) were included. The only significant independent predictors of late success were the presence of sinus rhythm (p < 0.04) and the absence of calcium at the valve (p < 0.001). In conclusion, the best results 5 years after mitral balloon valvulotomy are observed in patients with non calcified valve and sinus rhythm.