The plasma neutrophil elastase levels are elevated in sarcoidosis as the author reported earlier. This study looks at the prognostic value of the plasma neutrophil elastase levels in 29 patients with lung sarcoidosis; in 18 (61.3%) the levels were elevated (167 +/- 154 microg/L); healthy controls had values in the range from 32 to 56 microg/L. Most of the patients (86.2%) had lung parenchymal sarcoidosis, i.e. radiologic stage II and III. The frequency of increased BAL neutrophils in the high plasma elastase group was higher than in the low elastase group of sarcoidosis patients, but the difference did not reach a statistical significance. The mean follow-up period was 13.5 (range 6-30) months. The patients with elevated plasma neutrophil elastase levels did not show any difference in comparison with the group with the levels within normal limits in view of the results of the lung functional parameters (FVC, FEV1, DLCO, and paO2) or the chest radiographic imaging. Neither group showed statistically significant changes in the lung function tests and both groups showed a complete or nearly complete resolution of the chest radiologic findings in the follow-up period. The measurement of plasma leukocyte elastase levels showed no prognostic value in sarcoidosis patients examined.