A case report is presented.This report documents a case of complete traumatic anterior lumbosacral joint dislocation with the sacralization of L5.Traumatic anterior dislocation of the lumbosacral joint is a rare spondylolisthesis. The strategy for surgical treatment of traumatic dislocation of the lumbosacral joint remains controversial.A case of a 29-year-old man sustaining complete traumatic lumbosacral joint dislocation with the sacralization of L5 was treated successfully. Indirect radiologic signs such as bilateral multiple transverse process fractures were strongly suggestive of the diagnosis, which was further confirmed by 3-dimensional-computed tomography scan. This complete spondylolisthesis induced the instabilities of the entire soft tissues and caused severe cauda equina syndrome. The patient underwent an open reduction, decompression, and posterior fixation. Bilateral disrupted nerve roots were partly repaired simultaneously.The patient successfully underwent surgery. An anatomically aligned and preserved solid spinal fusion was obtained during a 17-month follow-up. The patient had neurologic improvement in hip extension and knee flexion, and also could walk with an ankle brace.Posterior instrumentation with the rod and screw system is considered a useful method for the management of complete traumatic anterior lumbosacral joint dislocation. However, prognosis is correlated with the initial neurologic status and the severity of other associated injuries.