Sacral insufficiency fracture (SIF) is an important and treatable cause of low back pain in at-risk groups and the elderly. We report rare demonstration of 'Honda sign' in fluoro-deoxy-glucose positron emission tomography-computed tomography (FDG PET-CT) in a case of lymphoma, which led to incidental diagnosis of SIF. Honda sign, which is classically described in bone scans in cases of SIF, was found in FDG PET-CT in our case. This suggests SIF should be suspected when similar FDG uptake pattern is encountered and may help in early detection and management of SIF.