We examined the immediate results and 2-year follow-up of percutaneous transvenous mitral commissurotomy (PTMC) using the Inoue balloon (IB) and double-balloon (DB) techniques. Short-term comparisons have been described, but long-term comparisons have not been available. PTMC was performed in 208 adult patients with symptomatic mitral stenosis (MS) and mitral valve area (MVA) of 0.94 +/- 0.2 cm2, by use of the IB in 157 (73.4%) and the DB technique in 56 (26.3%). Procedures were performed successfully and without complications in 198 (93%) cases. Adequate mitral dilatation (MVA = 1.6 cm2) without significant regurgitation was obtained in 179 (86%) of 192 patients. The final MVA was 2.0 +/- 0.43 cm2 after IB and 2.06 +/- 0.51 cm2 after DB (not significant). Technical difficulties and complications were more frequent with DB (16% vs 3.8%; p<0.001). Severe mitral regurgitation (grade III to IV) occurred in 4.6% of IB and 4.1% of DB (not significant), whereas grade 1 mitral regurgitation was greater with IB (21% vs 10.2%; p=0.01). A total of 172 patients were monitored an average of 23.8 +/- 10.6 months, with 83% in New York Heart Association functional class 1, echocardiographic MVA of 1.84 +/- 0.44 cm2, and restenosis rate of 22% at 36 months. PTMC is a safe, effective treatment for symptomatic MS. Results of both IB and DB techniques are similar, but the IB is simpler and safer, Long-term clinical improvement is maintained, although the restenosis rate seems to be progressive and related to inadequate immediate results.