PURPOSE: We evaluated whether 18F-FDG-PET altered stage classification, management, and prognostic stratification of newly diagnosed small cell lung cancer (SCLC). PROCEDURES: We identified 46 consecutive patients undergoing staging positron emission tomography for SCLC from 1993-2008 inclusive. Updated survival data from the state Cancer Registry was available on 42 of 46 patients. RESULTS: PET altered stage classification in 12 of 46 (26%) patients. PET altered treatment modality in nine patients, and the target mediastinal radiation field in another three patients. Therefore, PET altered management in 12 of 46 (26%) patients. Patients with limited disease (LD) on pre-PET staging had significantly longer overall survival (OS) than those upstaged to extensive disease (ED; median 18.6 months versus 5.7 months; log-rank p < 0.0001). In patients with ED on pre-PET staging, those downstaged to LD by PET had significantly longer OS than those with ED on PET (median 10.9 months versus 5.9 months; log-rank p = 0.037). CONCLUSION: PET had a major impact on stage classification, management, and prognostic stratification of newly diagnosed SCLC.