In a double-blind, placebo-controlled study, we assessed the efficacy of inhaled budesonide on the course of newly diagnosed pulmonary sarcoidosis and whether budesonide treatment could postpone oral corticosteroid treatment. We evaluated: 1) symptoms; 2) chest radiography; 3) angiotensin-converting enzyme (ACE) in serum; and 4) lung function. Patients with histologically confirmed pulmonary sarcoidosis with chest radiographic stages I, II or III, and with an abnormal lung function (inspiratory vital capacity (IVC) < 79% of predicted or transfer factor of the lungs for carbon monoxide (TL,CO) < 77% pred) were included. Patients with radiographic stage II or III but with normal lung function were included when more than 20% of the total cell population in bronchoalveolar lavage fluid (BALF) was lymphocytes. Forty seven patients received placebo or budesonide (1.2 mg) once daily via a Nebuhaler for 6 months, followed by 6 months without treatment. Based on predetermined criteria, 11 patients were excluded during the blind treatment period as they needed oral prednisone: seven (28%) patients in the placebo group (n = 25) and four (18%) patients in the budesonide group (n = 22). Patient's Global Clinical Impression (GCI) score showed a significant difference in favour of budesonide. IVC showed a significant difference of 7.9% predicted between the two groups during the active treatment period. This difference persisted during follow-up, when the difference was 9.4% pred. TL,CO remained nearly unchanged over time, with no difference between the groups. Improvements in chest radiographic appearance and changes in serum ACE were similar for the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)