The predictive value of serum sIL-2R level for radiologic and functional outcome of pulmonary sarcoidosis was evaluated in the 32 untreated patients. The median follow-up period in these patients was 38 months (range, 6 to 100 months). The median sIL-2R level at presentation in this group was 1,228 U/mL (range, 345 to 4,410 months). Fifteen patients showed a spontaneous normalization of their chest radiograph within 2 years (group B1), 11 patients did not show normalization within 2 years (regarded as “chronic disease”; group B2), 4 patients had a follow-up < 2 years, and in 2 patients no chest radiograph was available for this evaluation. No difference in sIL-2R level was found between group B1 (1,371 U/mL; range, 400 to 4,410 U/mL) and group B2 (1,253 U/mL; range, 814 to 3,340 U/mL). Subsequently, we analyzed the radiographic stage at the end of the follow-up period in both groups. Patients showing a final normalization of their chest radiograph tended to have higher initial sIL-2R levels compared to patients with persistent abnormalities, but this difference did not reach statistical significance (1,375 U/mL [range, 400 to 4,410 U/mL] vs 969 U/mL [range, 814 to 3,340 U/mL]; p = 0.2). Further, analysis of lung function at the end of the follow-up period showed that 63.6%, 7.7%, and 47.4% of the patients had an obstruction, a restriction, and gas exchange abnormalities, respectively. No significant difference in sIL-2R levels between patients with and without lung function impairment was found in any of the three categories (p = 0.5, p = 0.9, and p = 0.9, respectively). Finally, classifying patients as those having lone pulmonary sarcoidosis and those with extrapulmonary manifestations, the above-mentioned analysis did not reveal additional differences.