Many conditions may weaken bone and predispose to insufficiency fractures, including corticosteroids, radiation therapy, and rheumatoid arthritis, but osteoporosis is the main risk factor. Sacral insufficiency fractures (SIF) that usually present as nonspecific pelvic pain or low back pain are often overlooked in the elderly women with osteoporosis who have sustained minimal or no trauma. Diagnosis of SIF is difficult since the onset is mild, and usually discomfort is attributed to degenerative lumbar spine disease, spinal stenosis, vertebral compression fracture, or neoplasm. So a high index of clinical suspicion of SIF is required to avoid unnecessary diagnostic procedures. In most patients with SIF, bed rest, non-weight bearing ambulation, symptomatic treatment, and therapy for osteoporosis resulted in rapid improvement, and long-term follow-up of this fractures shows usually benign outcome. We are reporting a case of delayed detection of sacral fractures in osteoporotic woman.