Sarcoidosis, the possibility of its spontaneous remission, and its responsiveness to corticosteroid and other drug therapies are discussed. Sarcoidosis is a disease of unknown etiology characterized histologicaly by a granulomatous process with cellular infiltration. The granulomatous changes may remit spontaneously or may develop into fibrosis that, at times, is severe; factors that influence these progressions of the disease are not known. Cellular and humoral immunological abnormalities may be associated with this disease. Any organ can be affected although there is a high frequency of pulmonary involvement. Sarcoidosis may be benign and remit spontaneously in as many as 70% to 80% of cases, but the overall case fatality rate can be as high as 10%. Corticosteroids, the most effective therapy, cause temporary remission of the granulomatous changes but do not influence established fibrosis. Corticosteroids only temporarily influence the natural progression of sarcoidosis; however, corticosteroid therapy can preserve the function of vital organs. Other forms of treatment, such as chloroquine, methotrexate, oxyphenbutazone, allopurinol and levamisole hydrochloride, also produce remissions of the granulomatous infiltrate of sarcoidosis but offer no therapeutic advantages over corticosteroids. The decision to treat is often a difficult one, since corticosteroids and these other therapies have potentially hazardous side effects.