Since May 1991 to July 1992, 83 patients (mean age 49 +/- 13 years, 17 males and 66 females) underwent percutaneous mitral valvuloplasty according to Inoue's technique. Following Wilkins' criteria echo-score was < or = 8 in 46 patients and mono-commissural calcifications were present in 8 cases. Sixteen (19%) patients had previous surgical mitral commissurotomy and 15 (18%) had previous embolic events. The indications for the procedure were given on the basis of the echo-score (ideal cases with score < or = 8). All patients but 2 were successfully treated. Two patients who developed mitral regurgitation grade 3+/4+ were referred to elective surgery. Mitral valve area increased from 1.1 +/- 0.2 to 2 +/- 0.3 cm2 (p < 0.001) and transvalvular pressure gradient fell from 16 +/- 5 to 6 +/- 3 mmHg (p < 0.001). Patients with previous surgical commissurotomy had a lower increase in mitral valve area than patients without previous surgery (p < 0.02). Patients with echo-score > 8 presented a more evident increase in mitral regurgitation than patients with good valvular anatomy, even if this difference was not significant. At 6 and 12 month follow-up respectively 2 and 1 restenosis occurred, but in 1 of these cases the residual valvular area was > 1.5 cm2. The authors conclude that in selected patients with mitral stenosis percutaneous mitral valvuloplasty seems to be an effective and safe treatment. Furthermore, immediate and middle-term results show that this technique can be performed without adjunctive risks and with satisfactory results also in cases of no ideal clinical and/or valvular conditions (echo-score > 8, previous surgical commissurotomy, history of embolism, mono-commissural calcifications).