Purpose: To evaluate any potential value of 2-deoxy-2-[18F] fluoro-d-glucose with positron emission tomography/computerized tomography (FDG PET/CT) in staging of patients with Pancoast tumors and to investigate the relationship between volume-based quantitative PET parameters and prognosis. Materials and Methods: The authors retrospectively reviewed data of the 47 patients with Pancoast tumors who underwent initial staging by conventional imaging methods and FDG PET/CT. FDG-PET images were visually and quantitatively evaluated, and metabolic tumor volume (MTV), total lesion glycolysis, and maximum standardized uptake values of primary tumors were calculated. The correlations between quantitative PET parameters and tumor stages, as well as overall survival, were analyzed. Results: By detecting unknown distant metastasis, PET/CT upstaged 21% of patients. The sensitivity and specificity for detection of lymphatic involvement were 100% and 83.75%, respectively. Having surgery (p=0.01) and being at an early stage (p=0.004) were the most predictive factors for overall survival. Although there was no significant correlation between quantitative PET parameters and overall survival, MTV was the most powerful discriminator for operability and preoperative staging (p<0.05). Conclusions: FDG-PET imaging was found to be a valuable method for an accurate staging in the management of patients with Pancoast tumor. Having surgery and being at an early stage at presentation were found to be significant predictors for survival. Quantitative metabolic parameters may contribute to clarification of operable patient subgroups having an early disease stage with low MTV.