Legalization of cannabis' medicinal use is rapidly increasing worldwide, raising the need to evaluate medical implications of cannabis. Currently, evidence supports cannabis and its active ingredients as immune-modulating agents, affecting T-cells, B-cells, monocytes, and microglia cells, causing an overall reduction in pro-inflammatory cytokine expression and an increase in anti-inflammatory cytokines. Due to the supporting evidence of cannabinoids as an immune-modulating agent, research focusing on cannabinoids and autoimmunity has emerged. Several clinical trials in multiple sclerosis, inflammatory bowel disease, and fibromyalgia suggest cannabis' effectiveness as an immune-modulator. However, contradicting results and lack of large-scale clinical trials obscure these results. Although lacking clinical research, in vitro and in vivo experiments in rheumatoid arthritis, diabetes type 1, and systemic sclerosis demonstrate a correlation between disease activity and cannabinoids.