Over the past decade, there has been an increasing evidence of false-positive FDG uptake in several infectious diseases and aseptic inflammatory processes. With the widespread application of FDG-PET imaging in oncology, the interpreting physicians have come across these conditions frequently leading to false-positive diagnosis. Such conditions can coexist with metastatic lesions in patients with cancer, and hence, early and accurate diagnosis or exclusion of infection and inflammation is of utmost importance for the optimal management of these patients. Also, this powerful imaging modality can play an invaluable role for the appropriate management of these complicated benign conditions. The present communication on this non-oncological application of FDG is intended as an educative primer for practicing oncologists on this very important aspect of PET-CT imaging with an ultimate aim for bettering patient management.