We compared treadmill exercise stress testing (EST) in 28 medically screened, chronic cocaine users with the cardiovascular effects of an IV cocaine challenge (25 mg or 50 mg). All subjects had a clinically normal EST and echocardiography (except 2 subjects had septal wall hypokinesis). The EST produced significantly greater increases in heart rate and rate-pressure product than did the cocaine challenges. These findings suggest that EST may not provide additional diagnostic information in medically screened cocaine users. EST may cause more cardiac work (indicated by heart rate and blood pressure) than intravenous cocaine (at the doses in this study).