Recent case series have identified the presence of atypical insufficiency fractures at the diaphyseal femur of osteoporotic patients, which are possibly related to the long-term use of biphosphonates. We present images of a 72-year-old woman with a history of colon cancer and osteoporosis referred for bone scintigraphy because of bilateral thigh pain. No trauma or intense exercise was reported. Bone scan revealed bilateral femoral shaft stress fractures, which were confirmed by plain radiographs. In oncologic patients with osteoporosis referred for bone scintigraphy, atypical stress fractures should be included in the differential diagnosis of focal findings in the diaphyseal femur.