Background The added value of preoperative PET/CT for the overall survival of patients with resectable non-small cell lung cancer (NSCLC) is unknown. Purpose To investigate the association of the use of preoperative PET/CT on survival of patients with resectable stage I-IIIB NSCLC. Materials and Methods In this retrospective study, patients with resectable stage I-IIIB NSCLC who underwent thoracic surgery from January 1, 2009, to December 31, 2018, from the Taiwan Cancer Registry were included. The last follow-up date was December 31, 2019. Patients were categorized into two groups according to whether they underwent preoperative metabolic imaging with fluorine 18 fluorodeoxyglucose PET/CT. Patients who did not undergo preoperative imaging were used as the control group. The primary outcome of interest was all-cause mortality. Patients in both groups were propensity score matched at a ratio of 1:1. Matching variables used were sex, age, histologic findings, American Joint Committee on Cancer clinical stage, cT stage, cN stage, current and past smoker history, adjuvant chemotherapy, adjuvant chemoradiation, Charlson comorbidity index, and hospital type. Survival curves were generated using the Kaplan-Meier method and compared using the log-rank test. Results In the matched cohort, 6754 patients (3349 men, mean age ± SD: 64 years ± 11) underwent PET/CT and 6754 did not (3362 men, mean age: 64 years ± 11). In adjusted analysis, patients with stage IIIA or IIIB NSCLC and preoperative PET/CT had a lower risk of death versus those without PET/CT (for stage IIIA: hazard ratio [HR] = 0.90 [95% CI: 0.79, 0.94], P = .02; for stage IIIB: HR = 0.80 [95% CI: 0.71, 0.90], P < .01). There was no improvement in a lower risk of death for patients with stage I-II NSCLC (after multivariable adjustment, the HR was 1.19 [95% CI: 0.89, 1.30], P = .65). Conclusion Use of preoperative PET/CT was associated with lower risk of death in patients with stage IIIA-IIIB non-small cell lung cancer compared with those without preoperative PET/CT. © RSNA, 2022 Online supplemental material is available for this article.