Eight patients with acute exacerbations of lupus nephritis were treated with nine courses of alternate day intravenous methylprednisolone pulse therapy, for three doses of 30 mg/kg/day. They were followed for 24 to 68 months (mean 35.6) post pulse. Stabilization of renal function was observed. Proteinuria declined, antinuclear antibody titers fell and low serum complement levels improved. Steroids were discontinued by 24 months in four patients, and switched to alternate day therapy in the remaining five patients. No patient required the addition of cytotoxic therapy. Transient post pulse elevation of serum creatine was observed with return to pre pulse renal function by 1 month. Exacerbation of hypertension in two of the four known hypertensive patients occurred during pulse therapy; in one patient, this was associated with angina. No other untoward side effects were observed. In our experience, pulse therapy is an effective form of treatment in a subset of patients with lupus nephritis who have had recent worsening renal function. Pulse therapy may allow such patients to avoid the hazards associated with conventional long-term high dose oral corticosteroids as well as those of cytotoxic agents.