Abstract: ¹⁸F-fluorodeoxyglucose (FDG) PET/CT is a non-invasive imaging modality that is widely used to assess lung cancer. This technique provides valuable insights into tumor heterogeneity and is thus a fundamental tool for the early diagnosis, accurate staging, early therapeutic response assessment, and prognostic evaluation of lung cancer. In PET/CT, semi-quantitative evaluation is commonly used to assess ¹⁸F-FDG uptake in tumors. The process utilizes objective parameters to depict tumor metabolic characteristics. However, in multi-center analyses of ¹⁸F-FDG PET/CT images, the standardization of uptake value proves challenging, thereby hindering the widespread implementation of semi-quantitative evaluation in clinical practice. Conversely, visual evaluation method is a simpler, more feasible, and highly repeatable alternative that is less susceptible to external factors. In this study, the author critically appraises the application and limitations of ¹⁸F-FDG uptake evaluation in PET/CT imaging of lung cancer.