Objective To assess the value of ¹⁸F-FDG PET/CT for pre-operative evaluation of pancreatic adenocarcinoma and its effects on the therapeutic decision. Methods A retrospective analysis of clinical dada on 89 patients with pathology or biopsy-proven primary pancreatic adenocarcinoma and complete hospital records [including abdominal contrast-enhanced CT (ce-CT) and ¹⁸F-FDG PET/CT]. 29 cases were proved by operations to have surgical indications and 60 cases were proved by operations or follow-ups to have no surgical indication. First, pre-operative distant metastases and surgical indications were assessed via ce-CT, ¹⁸F-FDG PET/CT, and ce-CT combined with ¹⁸F-FDG PET/CT for patients with pancreatic adenocarcinoma. The efficacy of three methods was compared with χ2 test. Second, the effects of ce-CT combined with ¹⁸F-FDG PET/CT on the therapeutic decision were assessed. Results The accuracy rates of ce-CT, ¹⁸F-FDG PET/CT, and ce-CT combined with ¹⁸F-FDG PET/CT for evaluating the distant metastasis of pancreatic adenocarcinoma were 73.0%, 88.8%, and 92.1%, respectively (χ2=14.2, P=0.001). The accuracy rates for evaluating the surgical indication were 68.5%, 73.0%, and 85.4%, respectively (χ2=7.4, P=0.025). Of 57 patients who were evaluated by ce-CT to have surgical indications, 28 were proved by operations to have no surgical indication and 15 of them were correctly identified by the combination of ¹⁸F-FDG PET/CT. Of 29 patients who were evaluated by ce-CT to have no surgical indication, all of them were proven by operations or follow-ups to have no surgical indication. Ce-CT combined with PET/CT did not change the evaluation results. Conclusion For patients with pancreatic adenocarcinoma who are pre-operatively evaluated by ce-CT to have surgical indications, ¹⁸F-FDG PET/CT examination is necessary.