Cannabis ( Cannabis sativa/indica), also known as marijuana, has been used for medicinal and recreational purposes for millennia. There has been a recent trend to legalize the use of cannabis, as illustrated by the recent legalization votes in numerous states in the United States and legislation in Canada to allow recreational cannabis use. With this increasing consumption of cannabis, dermatologists will see increased pressure to prescribe cannabis and will see the side effects of cannabis use with greater frequency. There are several approved medical indications for cannabis use, including psoriasis, lupus, nail-patella syndrome, and severe pain. In addition, very preliminary studies have suggested cannabis and its derivatives might have use in acne, dermatitis, pruritus, wound healing, and skin cancer. Further well-controlled studies are required to explore these potential uses. Conversely, the side effects of cannabis use are relatively well documented, and dermatologists should be aware of these presentations. Side effects of cannabis use include cannabis allergy manifesting as urticaria and pruritus, cannabis arteritis presenting with necrosis and ulcers, and oral cancers from cannabis smoke. In this review, we summarize some of the studies and reports regarding the medicinal uses of cannabis in the dermatology clinic and some of the side effects that might present more often to dermatologists as the use of cannabis increases.