Thirty eight states have legalized marijuana for medical use. Eighteen states and the District of Columbia have legalized marijuana for recreational purposes. Inevitably, some of these marijuana users will be treated by the dentist. Are there any drug interactions between marijuana and dental drugs? Is marijuana addicting? What is the effect of marijuana on driving ability? This brief presentation will discuss some of the concerns about marijuana use/abuse, its bearing on dental treatment, and a pharmacologic basis for medical uses.