Brown tumors, or osteoclastomas, are erosive bony lesions arising as a complication of hyperparathyroidism (HPT). In patients with end-stage renal disease (ESRD), brown tumors are classic skeletal manifestations usually seen in severe forms of secondary HPT. However, involvement of the spine is considered extremely rare. We report a long-term hemodialysis case, in which cauda equina compression developed due to a sacral brown tumor. A decompressive surgery and subtotal parathyroidectomy were indicated to preserve neurologic function, and to ensure remineralization of the lesion. This case illustrates that, though rare, brown tumors should be considered in uremic patients with neurological symptoms. Emergent decompressive surgery is required to remove pressure on neurological structures and to stabilize the spine.