A 67-year-old woman with a long history of back pain began a walking program for exercise. Six weeks later, she experienced pain in the posterior aspect of her left thigh that became increasingly severe. She was referred to an orthopedic surgeon, who ordered a plain radiograph, the findings of which were reported as normal. He found localized tenderness in the upper third of the posterior thigh. Bone scintigraphy revealed a localized area of increased uptake at the site, and computed tomography (CT) showed calcification in the tendon of the gluteus maximus at its insertion into the posterior cortex of the left femur. This was thought to be consistent with gluteal tendinopathy, because it is similar to previously reported cases.