Objective: This study aimsto determine the prognostic value of metabolic volumetric 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) parameters of the primary tumor, including metabolic tumor volume (MTV) and total lesion glycolysis (TLG) in patients with non-small cell lung cancer (NSCLC) patients. Material and Methods: The study included a total of 102 patients who underwent PET/CT for staging. Histopathological diagnosis, stage of disease, survival time, maximum standard uptake value, MTV, and TLG values of the primary tumor were documented. The Kaplan-Meier test was used to examine the relationships between overall survival (OS) with PET/CT parameters and Tumor-Node-Metastasis stages. Univariate and multivariate Cox regression analyses were applied, and the association between OS with metabolic volumetric PET/CT parameters was estimated. Results: During the follow-up period, 93 (91.17%) patients died. All patients had a median OS of 10.15 months (range 0.5-74 months), whereas patients with M1 disease had a median OS of 7 months (range 0.5-56 months). The majority of (79.41%) patients had advanced-stage disease. Statistically, the mean MTV (p=0.012) and TLG (p=0.037) values at the early stage (Stage I-II) were significantly lower than the locally advanced and advanced (Stage III-IV) stage. In univariate analysis, elder age (p=0.004), advanced stage (p<0.001), lack of the operable (p<0.001), high MTV (p<0.001), and TLG (p<0.001) values were significantly correlated with poor OS. In multivariate analysis, stage of the disease (p<0.05), age (p=0.004), operable (p=0.022), and TLG (p=0.0019) values were found to be the independent predictors for OS. Conclusion: In patients with NSCLC, MTV and TLG of the primary tumor are suitable parameters to predict prognosis at first diagnosis. Particularly high level of TLG was independently related to poor prognosis.