To assess the natural history of hypertrophic cardiomyopathy (HC) in the elderly, we reviewed clinical, electrocardiographic and hemodynamic data from 21 patients over 60 years of age at diagnosis who were studied since 1970. Comparison with 95 younger patients (less than 60 years) showed that a greater proportion of older patients had exertional angina and atrioventricular conduction delay at time of diagnosis. During a mean follow-up of 9 +/- 6 years, mortality from cardiac causes was 33% (7 out of 21) in patients over 60 years of age and 23% (22 out of 95) in younger patients (NS). Univariate analysis showed that functional class and hemodynamic indices of right- and left-sided heart impairment were associated with a poor prognosis in the elderly. We conclude that: (1) presenting features and outcome of patients with HC over 60 years of age do not differ significantly from those of younger patients; (2) functional class and measurements of cardiac function are significant predictors of death in the elderly.