Preclinical studies have shown cocaethylene (the ethyl ester of benzoylecgonine) to produce pharmacologic effects of similar magnitude to those of cocaine. These observations, however, cannot establish whether or not cocaethylene produces cocaine-like subjective effects. We report the results of experiments in which three healthy male, paid volunteers were intravenously injected with the water soluble fumarate salt of cocaethylene in escalating doses. Subjective effects and cardiovascular parameters were the dependent variables. The maximal dose of cocaethylene base administered (0.25 mg/kg) produced subjective effects that were judged as milder and tachycardic effects that were comparable to those produced by the intravenous injection of an equivalent dose (0.25 mg/kg) of cocaine base.