Kikuchi’s disease is a self-limiting benign disease characterized by cervical lymphadenopathy, but it can be mistaken for malignant disease, and when involved lymph nodes are unusually located, diagnosis can be more difficult. The authors report the case of a 19-year-old man with Kikuchi’s disease, who had isolated intra- abdominal lymphadenopathy and increased 18-fluoro-deoxyglucose (FDG) uptake in positron emission tomography- computed tomography (PET-CT). Although its incidence is extremely rare, intra-abdominal Kikuchi’s disease with increased FDG uptake in PET-CT image should be considered in the differential diagnosis when constitutional symptoms mimic those of malignant lymphoma. (Nucl Med Mol Imaging 2009;43(4):363-365)