Although there are some data on the cardiovascular profile of bupropion, a non-nicotine-based pharmacotherapy for smoking cessation, detailed studies of its specifically cardiac effects are lacking. In particular, the direct action of this agent on human myocardial contractility is not known. Therefore, we investigated the effects of bupropion on human cardiac tissue in vitro. Our results suggest that bupropion exerts indirect sympathomimetic activity producing positive inotropic effects in human myocardium most probably by catecholamine release.