The title of this Argentine film would seem to suggest an exploitive anti-drug tract. While it's true that Marihuana leans towards stridency and unsubtlety, it has a lot more going for than, say, Reefer Madness. Lopez Lagar plays a prominent surgeon whose pot-addict wife is murdered under sordid circumstances. Vowing revenge, the doctor ventures into Buenos Aires' drug subculture to find his wife's killer. He finds a few faithful friends along the way, notably a singer (Fanny Navarro) and a pianist (Nathan Pinzon). Unfortunately, the surgeon becomes the very thing he despises when he takes to the weed himself. The climax pits the good guys against the evil forces of a drug-dealer (Eduardo Cuitino) and his gang. Some intentional humor is provided by Hector Quintanilla as a goofy doper.