The objective of this study was to retrospectively explore the safety and efficacy of leflunomide (LEF) in outpatients with systemic lupus erythematosus (SLE). Eighteen SLE females received LEF, open label, 100 mg/day loading dose for 3 days followed by 20 mg per day. Patients were evaluated for safety and efficacy after 2-3 months of therapy. The mean age was 42.6 y and mean disease duration 7.9 y. ACR criteria were met by 15/18. Four patients stopped LEF during the observation period. Ten of 14 LEF-treated patients had subjective improvement with 9/14 patients achieving lower SLEDAI scores. The mean SLEDAI decreased by 2.1 (P=0.005) and the mean ESR decreased by 9mm/h (P=0.02). Prednisone dosages could be reduced in 2/5 subjects without a flare. No organ-threatening or life-threatening side effects were seen in our patients. Diarrhea occurred in seven patients (two stopped LEF), rash occurred in one patient (stopped LEF), one patient stopped LEF for reasons not related to therapy. Blood pressure was unchanged. Leflunomide was efficacious and safe in this cohort of SLE patients after 2-3 months of therapy. Placebo-controlled trials of longer duration are indicated.