One hundred eighty-two patients fulfilling the American Rheumatism Association criteria for the classification of systemic lupus erythematosus (SLE) were followed prospectively. Sixty-seven had the onset of SLE before age 21, 32 before age 16, and 35 between age 16 and 20. All patients received similar therapy. Only 4 patients received cytotoxic agents. Malar blush, cellular casts, and profuse proteinuria were significantly more common in the 0-15 compared to the adult group (age 21 or older). Five-year survival was 100% for children with membranous or focal lupus nephritis and 85% for diffuse proliferative lupus nephritis.