Sacral insufficiency fractures are a rare type of osteoporotic fracture which mainly occurs in elderly osteoporotic patients without specific trauma. Low back and hip pain are the most frequent complaints associated with sacral insufficiency fracture. Thus, if sacral insufficiency fracture is not considered in the differential diagnosis, the diagnosis may be difficult or delayed. In this case report, we present a patient who attended our outpatient clinic with low back and leg pain and who was first diagnosed as having lumbosacral pathology according to magnetic resonance imaging findings. Our aim was to point out the difficulty in diagnosing sacral fracture and the delay in diagnosis and treatment. Turk J Phys Med Rehab 2011;57 Suppl 2: 377-4.