Herbiniaux, a Belgian obstetrician, noted a bone prominence of the sacrum that was obstructing labor in 1782. The term spondylolisthesis was first used by Dr. Kilian in 1854 and is derived from the Greek spondylos (vertebrae) and olisthy (to slip or slide). Spondylolysis occurs with a prevalence of 4% to 6% in the general population. Although the etiology of this lesion is unclear, it has been shown to have both hereditary and acquired risk factors. Prevalence is twice as high in females as in males, and prevalence increases in athletes participating in certain high-risk sports (1,2). Spondylolisthesis occurs in persons with bilateral spondylolysis; slip progression is greatest early in the life span (1). Predicting risk factors for progression of the slip has proven difficult, and slippage is uncommon in adults (3). The rehabilitation literature for nonsurgical treatment of the condition is sparse, and only a few randomized controlled trials exist (3,4). Rehabilitation involves bracing or exercises or both, in combination with education to the patient about the condition. The purpose of these treatments is to stabilize the spine, prohibit further slippage, decrease pain, and increase function. Most patients do well with conservative treatment regimen; however, it is estimated that 9% to 15% of patients with spondylolysis or low-grade spondylolisthesis need surgery (3). The purpose of this brief chapter is to comment on the natural history in patients with spondylolysis and spondylolisthesis and to summarize the evidence of prescribed brace and exercise regimens.