ABSTRACT Objective: To investigate the effect of 18 F-FDG PET/CT imaging combined with 3D-printed templates on the biopsy results and diagnostic efffcacy in patients with lung tumors. Methods: This was a comparative study. A total of 80 patients with suspected lung tumors admitted to Baoding NO.1 Central Hospital from May 2022 to December 2023 were selected as the research subjects and divided into the study group and the control group per different detection methods. Patients in the control group were treated with 18 F-FDG PET/CT imaging-guided percutaneous aspiration biopsy of the lung, while those in the observation group underwent 18 F-FDG PET/CT imaging-guided percutaneous aspiration biopsy of the lung combined with 3D printed templates. Afterward, the biopsy results of the two groups and their diagnostic efffcacy and complications were compared. Results: No signiffcant differences were observed in tissue length and scanning time between the two groups (P>0.05). The operation time and number of biopsies in the observation group were less than those in the control group, with signiffcant differences (P<0.05). Meanwhile, there was no statistically signiffcant difference in speciffcity (15.00% vs. 27.50%) and misdiagnosis rate (2.50% vs. 10.00%) between the two groups (P>0.05). Moreover, the incidence of complications in the observation group was 5.00%, lower than the control group (7.50%), with no statistically signiffcant differences (χ2 =0.213, P=0.644). Conclusion: The observation group was found to have superior effect than control group, with fewer punctures and shorter puncture time, making it worthy of promotion in clinical application.