ABSTRACT Purpose: We aimed to comprehensively evaluate the effects of medical marijuana on symptoms that are relevant to movement disorders with a focus on Huntington disease (HD). Methods: A systematic review by literature search through PubMed and EBSCO electronic databases was conducted for relevant studies reported after 2002 on the effects of medical marijuana or cannabis use on tremor, spasm, spasticity, chorea, sleep quality and HD-specific rating scales. Study selection, quality assessment and data extraction was performed by three reviewers. Outcome measures were changes in psychomotor, and sleep related symptoms. The methodological quality of the included studies was evaluated. Results: A total of 22 studies were reviewed. There was...