A retrospective review of 55 patients with systemic lupus erythematosus (SLE) (45 girls and 10 boys) under age 18 (median age of onset; 12.2 years) seen at the Children's Hospital Medical Center (Boston, Mass.) over the past 20 years was done. Clinical presentation was similar to previous series, but atypical presentation was common. Certain unusual presentations (such as isolated hematopoietic abnormalities) often occurred and delayed diagnosis for years in some cases. The frequency of ARA clinical classification of SLE was different in children as compared to adults. We observed depression of lymphocyte count in many patients and encountered elevations of hepatic enzyme levels in others. Of the 55 patients reviewed, 9 have died and 8 have been lost to follow-up. Of the rest, 21 have mild to moderate disease and 17 have inactive or minimally active SLE, after a median length of follow-up of 8.8 years. In severe cases, using either corticosteroids and/or cytotoxic agents, a favorable prognosis was obtained. Our cumulative 5- and 10-year survival of 92 and 85%, respectively, equals or exceeds that of previous reports of childhood SLE.