The review is based on studies of pulmonary sarcoidosis from Denmark, Finland and Sweden during 1950-1982, focusing on the course and prognosis of the disease. Cases with acute onset with chest X-ray stage I, fever, arthritis and erythema nodosum had a 85-90% remission rate during the first two years. The overall 5 year remission rate for stage I was 82%, stage II 66% and stage III 30%. Among cases with stage I, 2-5%, and among cases with stage II and III, 6-10% developed chronic pulmonary disease. Patients with stage I had a normal mortality rate, whereas those with stage II, III and IV had a rate threefold higher than expected due to sarcoidosis-related cardiopulmonary complications.