“Medical” marijuana is approved in 21 states and the District of Columbia for numerous conditions, including glaucoma, Crohn disease, posttraumatic stress disorder, epilepsy, Alzheimer disease, and chemotherapy-induced nausea and vomiting. Both the number of states and the number of approved indications for medical marijuana are expected to increase. Physicians will bear the responsibility of prescribing marijuana and thus have an obligation to understand the issues involved in its “medicalization.”