Cannabis smoking is consistently increasing in Europe and after alcohol it is the most common recreational drug in the western world. Users and lay people believe that marijuana or hashish is safe. Over the past four decades, however, it has been well established that cannabis has pathophysiological effects on the cardiovascular system. Information concerning the link between cannabis consumption and myocardial infarction is limited and existing data are controversial on this topic. In our case report, we describe a case of a young man who after smoking marijuana experienced ST elevation myocardial infarction caused by acute thrombosis of the descending artery, submitted to efficacious primary coronary angioplasty.