Studies of immunosuppressive therapy, particularly mycophenolate mofetil (MMF), in membranous lupus nephritis (MLN) are limited. We report on our experience with primary (first-line) MMF therapy to induce and sustain renal remission in MLN with and without a concurrent proliferative lesion. Systemic lupus erythematosus (SLE) patients were studied, retrospectively, if treated with MMF for newly diagnosed MLN. Complete remission was defined as proteinuria less than 0.5 g/24 h, inactive urine sediment and normal estimated glomerular filtration rate. Response in pure MLN (Group I, n=10) was compared with mixed MLN and proliferative lupus nephritis (Group II, n=19). By 12 months, 4 (40%) patients in Group I and 7 (36.8%) in Group II achieved complete remission (P=0.87). One (10%) patient in Group I and 2 (10.5%) in Group II had worsening renal disease (P=0.97). Mean time to remission was more than seven months in both groups. The remaining patients had stable disease without improvement or worsening. Only 2 of 11 achieving initial remission had a relapse with an average of 28 months of follow-up after remission. Self-limited gastrointestinal symptoms occurred in 12 patients, none requiring withdrawal of the drug. Mycophenolate mofetil as a primary therapy in MLN was successful in inducing complete remission in about 40% of MLN, particularly in patients with mild proteinuria. However, 12 months of therapy was necessary for best outcomes. Response rate was not different in the presence or absence of a proliferative lesion.