Symptomatic mitral stenosis (MS) develops in 7% to 21% of patients after percutaneous mitral balloon valvotomy (PMV). Treatment options for these patients are surgical mitral valve replacement (MVR) or repeated PMV. However, no comparisons were made between these 2 procedures regarding long-term outcome. This retrospective study compares the long-term outcome of 888 patients with symptomatic MS after MVR or repeated PMV who underwent PMV from April 1988 to December 2003. Thirty-two patients subsequently underwent repeated PMV, and 59 patients underwent MVR for symptomatic MS. Mean follow-up was 85 +/- 43 months with a maximum follow-up of 15 years. Patients with MVR have more unfavorable clinical characteristics, including a higher incidence of atrial fibrillation and severe mitral regurgitation. Event-free survival was similar between the 2 groups up to 40 months after the procedure; 3-year event-free survival rates were 96.6% for MVR patients and 90.0% for repeated PMV patients (p = 0.215). However, after 40 months, the outcome was more favorable for MVR. Comparing MVR versus PMV, 6-year event-free survival rates were 93.0% versus 75.9% (p = 0.036), and 9-year event-free survival rates were 90.4% versus 36.0% (p <0.001). In conclusion, the long-term outcome of patients with symptomatic MS after previous PMV was more favorable after MVR than after repeated PMV. These data suggest that MVR may be the preferred mode of therapy in patients with unfavorable valve morphologic characteristics and no co-morbid disease.