It is well known that heroin overdose may cause rhabdomyolysis. Sometimes a myocardial involvement complicates its course. We report a case of heroin intoxication followed by rhabdomyolysis associated with myocardial injury, with symptoms, laboratory findings, ECG and echocardiography features of non-Q wave infarction. However, a 201 Tl myocardial scintigraphy, performed after patient discharging, did not show any abnormality. We think that heroin has a direct myotoxic effect on both myocardium and skeletal muscle. Yet we cannot exclude that hypoxia, acidosis, vasoconstrictive substances released by muscle necrosis, or hypersensitivity reactions associated with heroin or some of its adulterants are involved in myocardial injury.