This study aimed at evaluating the frequency of autoimmune disorders in Addison's disease. We have observed 180 patients (113 females, 67 males, aged 9-74 years) for 1 to 26 years. Tuberculosis was noted in 54 patients. Autoimmune disorders were found in 80 patients (44%); however, 125 (69%) patients were believed to have an autoimmune origin of adrenocortical insufficiency. In 20 patients two or more autoimmune disorders were found to coexist with Addison's disease.