3 out of 24 patients with mitral valve prolapse (MVP), mean age 25.7 +/- 3.1 displayed markedly thickened redundant and shaggy mitral leaflets in the two-dimensional echocardiogram. The anterior leaflet appeared in the parasternal long axis plane club-shaped in diastole. These three female patients had a history of ischemic stroke, which could be verified by CT-scanning. Suggestion is made that MVP and thickening of the valve is correlated with a higher risk for cerebral infarction.