We report a case of gouty tophus of the patella, a rare lesion, which was evaluated using positron emission tomography (PET). This modality, which uses a combination of an amino-acid analog emitter, L-[3-(18)F]-alpha-methyl tyrosine (FMT), which neglects malignancies, and a glucose analog emitter, (18)F-fluoro-2-deoxy-D-glucose (FDG), which neglects benign lesions, simulating the radiographic findings, may be useful for the preoperative evaluation of gouty tophus occurring in patella partita, including detection, differentiation from malignant tumors, and possible pathogenetic diagnosis.