Abstract: Pulse cyclophosphamide (PCP) is a well established method for the treatment of lupus nephritis. PCP seems to produce better results, and lesser side effects, than oral cytotoxic drugs. We present here, our experience with this method, in 51 patients. All patients had a WHO type IV histological lesion, on light microscopy. Proteinuria, hematuria, leucocyturia, casts, BUN, creatinine, and blood pressure were measured before starting PCP and after each one. The first and the last measurment were compared to each other by the Student paired t test. Cyciophosphamide. was given as 1000 mg per m2 of body surface, once per month. When a satisfactory result was, obtained, the gap between pulses was increased to 2 or 3 months. Prednisolone was administered, per os, as 1/2 mg per Kilogram of body weight. RESULTS: The mean follow up time was 17 months. The mean pulse per patient was 9 pulses. Proteinuria was improved in 80% of patients with t=4.110 and p<0.001. Hematuria improved in 84% of patients with t=5.049 and p<0.001. Leucocyturia improved in 73% of patients with t=2.101 and p<0.05. Casts improved in 89% of patients with t=5.040 and p<0. 001. Creatinine improved in 73% of patients with t=2.872 and p<0.01. The changes in abnormal BUN and blood pressure were not statistically significant. Side effects were minor: Nausea and vomiting after PCP, and moderate hair loss in some patients.