Sacral insufficiency fractures are often missed on initial presentation due to the clinician's reliance on x-rays to identify acute fractures or failure to consider the diagnosis. Patients often present with non-specific marked lumbosacral pain, mimicking lumbar strains, but may also present with pain in the buttock, hip, groin, or pelvis. Patients almost always have great difficulty or pain with ambulation if they are able to walk at all. The diagnosis of sacral insufficiency fractures must be considered in patients at risk for osteopenia and osteoporosis, especially in the elderly. However, insufficiency fractures may also be seen in patients who have undergone radiation to the pelvis, have demineralizing bone diseases, have used chronic steroids, or have other conditions that may weaken the bony pelvis. Patients typically present with severe sacropelvic pain that is sudden in onset with no or minimal history of trauma. Although uncommon, sacral insufficiency fracture can present with cauda equina syndrome. Given the diagnostic limitations of x-ray and CT to identify insufficiency fractures, MRI should be performed in patients where clinical suspicion of insufficiency fractures is present. Once identified, most sacral insufficiency fractures can be managed non-operatively with limited weight-bearing, rest, and pain control. Complete healing may take nine to twelve months. Sarcoplasty may be considered in patients with severe intractable pain, and operative fixation may be required in cases of neurological impairment.