The metallic commissurotome (MC) technique is a cheaper alternative to the Inoue balloon (IB) technique for percutaneous mitral valvuloplasty (PMV). There are no randomized trials comparing these techniques with longer follow-up of the patients. The objective of this study was to compare the immediate results and short- and medium-term follow-up of PMV using either the IB or the MC technique. Fifty patients with rheumatic mitral stenosis were randomly assigned to PMV using the IB (n = 27) or the MC (n = 23) technique. There were no significant differences between the groups regarding baseline clinical, echocardiographic, and hemodynamic data. Clinical and echocardiographic follow-up were done 6 months and 3 years after the procedure. The success rate was 100% in the IB group and 91.3% in the MC group (P = 0.15); two patients in the latter group developed mitral regurgitation grade 3/4, requiring elective surgery. The mean final mitral valve area was bigger in the MC group (2.17 +/- 0.13 vs. 2.00 +/- 0.36 cm2; P = 0.04), but after 6-month and 3-year follow-up, this difference was no longer significant (2.06 +/- 0.27 vs. 1.98 +/- 0.38 cm2, P = 0.22, and 1.86 +/- 0.32 vs. 1.87 +/- 0.34 cm2, P = 0.89, respectively). This finding suggests valve stretching as an important mechanism of valve dilation with the MC. Three patients in the MC group and two patients in the IB group (P = 0.65) developed mitral valve restenosis; one of them underwent repeat PMV and the other four, all asymptomatic, were clinically followed. PMV performed either with the IB or the MC technique is effective and provides excellent short- and medium-term outcomes regardless of the technique employed.