Hibernoma is a rare, benign, soft tissue tumor that is composed of brown fat. We report here on a case of hibernoma that arrose from the right psoas muscle along with the imaging features on computed tomography (CT), magnetic resonance imaging (MRI), and 2-deoxy-2 (F-18) fluoro-D-glucose positron emission tomography (FDG-PET). We suggest that a fat-containing mass with a curvilinear intratumoral vessel on the CT and MRI scans provides diagnostic clues for making the differential diagnosis of hibernoma, although these features may mimic malignancy.