A 45-year-old woman with congestive heart failure, in whom there was no evidence of coronary heart disease, valve disease, or other demonstrable cause of heart failure, was found to have taken high doses of dextroamphetamine over a long period. Withdrawal of amphetamine resulted in deterioration, suggesting a physical cardiac dependence on the drug. The clinical and autopsy findings are presented and the similarities to the myocarditis associated with pheochromocytoma are discussed. The evidence presented suggests a causal relationship between administration of dextroamphetamine and the cardiomyopathy.