According to the NIH scheme, the "evidence based medicine" standard in the treatment of severe proliferative lupus-nephritis is cyclophosphamide in combination with steroids. Undesired effects, therapy resistance, and deficient long-term effects underscore the necessity for the development of alternative therapies for the treatment of organ involvement. Mycophenolate mofetil (MMF) possesses the potential to decisively improve the therapeutic possibilities for systemic lupus erythematosus (SLE). On the basis of the available data, MMF represents an alternative to the current standard therapies for severe lupus-nephritises and shows less toxicity. MMF is also effective in patients with other manifestations refractory to conventional therapy. Questions remain unanswered on the optimal dosage and possible reduction in cases of remission. In addition, the duration of maintenance therapy is unclear. Therefore, large, prospective, randomized clinical studies in the treatment of lupus-nephritis with a sufficiently long follow-up phase are underway.