The objective of this study was to identify clinical predictors of response to initial mycophenolate mofetil (MMF) therapy for membranous lupus nephritis (MLN). We observed the clinical outcomes of patients in the Hopkins Lupus Cohort within the first year of initiation of treatment with MMF therapy for newly diagnosed MLN, classified according to the new International Society of Nephrology/Renal Pathology Society (ISN/RPS) 2003 classification. Complete renal remission was defined as proteinuria less than 500 mg/24 hours. Demographic, clinical, treatment and laboratory data were examined for their association with renal remission. Twenty-nine MLN patients treated with MMF were identified. Eleven (38%) patients achieved complete renal remission by 12 months. Of those taking hydroxychloroquine, 7/11 (64%) were in remission within 12 months compared to only 4/18 (22%) of those not on hyroxychloroquine (P = 0.036 based on a log-rank test). This association persisted after controlling for the presence of anti-ds-DNA (P = 0.026). Our results provide evidence that hydroxychloroquine has a benefit for renal remission when MMF is used as the initial therapy for MLN. Although hydroxychloroquine is frequently stopped in patients with lupus nephritis, this study suggests it should be started or maintained.