BACKGROUND Percutaneous mitral balloon commissurotomy (PMBC) remains the fust choice of treatment in appropriate candidates with mitral valve (MV) stenosis (MS) and ideal anatomy. The objective of this study was to identify the risk factors of MV restenosis in a large cohort of patients submitted to PMBC. METHODS This study reports a single tertiary-center experience which treated 1,794 consecutive patients. Procedural success was present when post-PMBC valve area was 15 cm³ with an angio- graphic mitral insufficiency of less than 3+. Restenosis was diagnosed when MV area was <1.5 cm³ or loss of 50% or more of the immediate procedural result aligned with the return/worsen symptoms of heart failure. Primary endpoint was to determine the pre-procedural inde. pendent predictors of restenosis after PMBC. RESULTS MV restenosis was observed in 26% of the cases (n = 483), and median follow-up duration was 9.03 years (0.33-23.38). Mean population age was 36.5 ± 12.8 years, mostly female (86.1%). Regarding echocardiography variables, only Wilkins score variables differ significantly (8.76±1.27 (6-14] vs 8,62±1.17(6-14); P=0.05). At multivariate analysis independent pre-procedural predictors of restenosis were: left atrial diameter (HR 1.03; 95% CI: 1.01-1.04; P<0.01), pre-procedure maximum gradient (HR: 1.01; 95% CI: 1.00- 1.03; P=0.02), and higher Wilkins-Block scores (HR: 1.37; 95% CI: 1.13- 1.66; P < 0.01). CONCLUSIONS Throughout more than 20 years' follow-up, MV restenosis was observed in one-fourth of the population undergoing PMBC. Preprocedure echocardiographic findings, including left atrial diameter, maximum valve gradient, and higher Wilkins scores were found to be the only independent predictors of this deleterious event.