Paget disease (PD) is a chronic disorder resulting in enlarged and misshapen bones, caused by disorganized bone remodeling. This case involves a 64-year-old man with prostatic adenocarcinoma and PD of some skeletal areas with increased uptake shown on 18 F-fluoro-methyl-choline (FMC) positron emission tomography/ computed tomography (PET/CT) performed for cancer restaging. Besides this feature, Paget disease may mimic metastases on PET/CT using various radiotracers, including 18 F-FMC PET/CT. In particular, this case highlights the potential of multiparametric disease characterization on PET. Therefore, in suspected cases, in which differential diagnosis is difficult, histology can be a helpful tool for diagnostic purposes.