Forty-four patients with newly discovered biopsy-proven pulmonary sarcoidosis in roentgenographic stage II (adenopathy and interstitial abnormalities) who also had abnormal pulmonary function (TLC and/or DCO less than 80 percent predicted) were assigned in alternate sequence to either a daily or alternate day prednisone treatment protocol. Both groups showed statistically significant improvement in pulmonary function (TLC, FVC, FEV1, DCO) at three or six months, but there were no significant differences between the two groups. Radiographic adenopathy and interstitial scores (interpreted by blinded readers in random sequence according to a quantitative scale) also showed significant improvement in both groups at three or six months, and again no significant difference was noted between the two groups. Thus, both daily and alternate day prednisone regimens were effective therapy for stage II sarcoidosis. Alternate day therapy may be the treatment of choice for those patients at high risk for significant adverse steroid effects.