Mycophenolate mofetil (MMF) is an inhibitor of inosine monophosphate dehydrogenase, which affects de novo purine synthesis and T- and B-cell proliferation. So far its efficacy and safety as an immunosuppressive treatment have been proven in organ transplantations and also in various autoimmune diseases. A literature search was conducted by using PubMed and the Cochrane library. This review focuses primarily on current treatment with MMF for systemic lupus erythematosus, systemic sclerosis, vasculitis and idiopathic inflammatory myopathies.