AIM: The aim of this study was to assess the frequency of indeterminate (18)F-fluorodeoxyglucose (FDG) accumulations on positron emission tomography (PET) and PET/computed tomography (CT) images in patients with pelvic pathologies. METHODS: We retrospectively evaluated 536 focal FDG accumulations of 166 PET/CT examinations. A consensus reading of PET/CT images, clinical data, and other imaging tests was the standard of reference to assess sensitivities and specificities of PET and PET/CT. Frequencies of indeterminate findings and intraobserver agreement were evaluated. CONCLUSION: PET/CT improves the anatomic delineation and the correct assignment of physiologic and pathologic uptake.