Marijuana is the most widely used illicit substance in the United States. Cardiovascular complications in association with marijuana use have been reported during the past three decades. In view of the elevated public interest in this drug's role in pharmacotherapy in the recent years and the aging population of long-term marijuana users from the late 1960s, encounters with marijuana-related cardiovascular adversities may be silently on the rise. The purpose of this article is to increase awareness of the potential of marijuana to lead to cardiovascular disease. Here, we will discuss the physiologic effects of marijuana and include a comprehensive review of the studies and case reports that provide supportive evidence for marijuana as a trigger of adverse cardiovascular events, including tachyarrhythmias, acute coronary syndrome, vascular complications, and even congenital heart defects.