A survey of familial occurrence of systemic lupus erythematosus (SLE) was conducted among 728 first-degree relatives of 102 SLE patients. All of the patients were from the rheumatology ward or outpatient clinic of Kaohsiung Medical College. Ten familial members (9.80%) in the 102 patients with SLE suffered from the same disease. Among them, one (20%) was from the 5 male patient families and 9 (9.28%) were from the 97 female patient families. The overall prevalence of SLE in first-degree relatives of SLE patients was 1.37% (10/728).