<p>Objectives: Recent studies have shown that mycophenolate mofetil (MMF) is similar to intravenous cyclophosphamide (IVC) for the treatment of lupus nephritis (LN), but that treatment response may vary according to location and race/ethnicity. Moreover, no studies have been conducted to compare the efficacy of MMF with that of IVC for a Japanese population. We therefore conducted a retrospective study to clarify the efficacy and safety of MMF compared with that of IVC for induction therapy for active LN, classes III and IV, in a Japanese population of 21 patients, 11 of whom received MMF and 10 IVC. Methods: The primary endpoint was expressed as the percentage of responders, who in turn were defined as the patients who met complete or partial response criteria according to the European consensus statement. The secondary endpoints comprised the renal activity component and serological activity. Results: The primary endpoint was achieved in nine (81.8 %) patients receiving MMF and in four (40.0 %) receiving IVC, with no significant difference between the two groups (p = 0.081), while there was also no significant difference between them in terms of secondary endpoints. However, the