Summary: Aim of the study: conducting a neuroanatomical study on the deterious effects of regular and chronic concomitant consumption of alcohol and cannabis on the prefrontal cortex and cerebellum hemisphere. Materials and methods: The study was conducted at the Institute of Forensic Medicine in Casablanca (IFM) for the period from January 2008 to January 2012. The study population consisted of all deaths following an accident or fall and having concomitant consumption of alcohol and cannabis (n = 228). Results: Of the 228 admitted to the IFM. We recorded 13 deaths with concomitant alcohol and cannabis consumption chronic and regularly. The average age was 28.84 years (SD: 0.73) with extreme ranging from 20 to 39 years, all were male. We found a score (2) in 10 cases, and score (1) in 3 cases. Conclusion: The neuroanatomical study showed the presence of variation in the number of neurons in the prefrontal cortex in 13 cases of people with the emergence of two scores: score (2) in 10 cases and score (1) in 3 cases while no structural change was found in the cerebellar hemisphere.