Oral health workers should be alert about the dangers of marijuana use in the screening of oral pathologies and methods of administration of similar clinical cases. The use of marijuana is for medicinal and recreational reasons. It is already known, and based on the literature, this plant causes besides medicinal advantages, oral health pathologies also. For carrying out the study, was committed a group of students, who examined clinically, 3 patients, that later were diagnosed. Reduced saliva, influenced by use of marijuana, encourages the show of xerostomia. In this way, this plant is a favorable factor for caries that at examined patients was currently, more than at 5 teeth. Dysplastic changes in the epithelium of the buccal mucosa were appearing as the result of the action of chemical factors of marijuana smoke. Inflammation of the gums, gingivitis sometimes called "fiery red", is the lesion that causes great pain. The use of anesthesia with epinephrine during dental procedures, to users of marijuana may cause acute anxiety or tachycardia. Candinda Albicans was promoted as the result of the presence of carbon hydroxide at the smoke of marijuana. Chronic marijuana usage causes pathologies mentioned above, at individuals who do not treat in time. Counseling and education of oral health workers and individual users or not, about these pathologies, represents the largest contribution in diagnostic routine oral work.