Images were obtained with Ga-67 and bronchopulmonary lavage performed in 21 patients with sarcoidosis (31 studies). The Ga-67 index, a semiquantitative criterion, was compared to a quantitative computer index based on lung:liver activity ratios; accuracy in predicting active alveolitis (defined by lavage lymphocyte counts) was assessed and differences between 24- and 48-hour studies examined. Computer activity ratios correlated well with the Ga-67 index, which had a sensitivity of 64%, specificity of 71%, and accuracy of 68% compared to 71%, 82%, and 77%, respectively, for the computer scores. Scores at 24 and 48 hours were similar. These results suggest that (a) Ga-67 scanning is useful in staging activity in pulmonary sarcoidosis, (b) quantitative computer scores are accurate in predicting disease activity, and (c) scanning can be performed 24 or 48 hours after injection.