In the absence of trauma, fracture of the acetabulum is a rare injury, and an isolated insufficiency fracture in the supra-acetabular region is extremely rare. We describe a 59-year-old postmenopausal woman with systemic lupus erythematosus (SLE) who developed a fracture in the roof of the acetabulum with underlying corticosteroid-induced bony insufficiency. Faint medullary sclerosis over the roof of the acetabulum was observed on plain roentgenograms. Diagnosis was made using magnetic resonance imaging. Irregular linear low signal intensity lines were observed on T1-weighted, T2-weighted, proton density, and contrast enhanced images, and these represented the fracture. The fracture healed with conservative management. Insufficiency fracture in this location should be suspected in an osteopenic woman with spontaneous hip pain.