During the 17 years from 1962 to 1979, 4403 closed mitral commissurotomies were performed at the Istanbul Thoracic Surgery Center in Istanbul, Turkey. There were 60 hospital deaths (1.36%), 30 cerebral emboli (0.68%), 14 peripheral emboli (0.31%), five instances of severe mitral regurgitation (0.11%) and improvement of at least one New York Heart Association Class level in 92.2% of the patients available for late follow-up 1 to 17 years later (mean 4.2 years). Closed mitral commissurotomy without cardiopulmonary bypass can be a safe and effective alternative to open mitral commissurotomy where circumstances dictate its use.