Learning Objectives: After studying this article, the participant should be able to: 1. Understand the natural history of obstetric brachial plexus injury with an emphasis on clinicopathologic features. 2. Develop an awareness of the indications and timing for both nonsurgical and surgical treatment. 3. Acquire knowledge of the current methodologies involved in primary and secondary brachial plexus reconstruction.Obstetric brachial plexus palsy is a potentially devastating form of cervical nerve injury that occurs in 0.38 to 2.6 births per thousand. In this review, we discuss fundamental clinicopathology and delve into the indications and methods of both nonsurgical and surgical strategies. An analysis of the major techniques of reconstruction is placed within the context of historical trends and a contemporaneous survey of the literature. On this basis, and given our own 12-year experience (with 415 surgically treated patients), several general conclusions can be made: (1) Early surgical intervention (3 to 6 months) is essential to optimizing long-term outcome in patients who have not had return of function in critical muscle groups. At Texas Children’s Hospital, we have developed an efficient multidisciplinary approach to primary brachial plexus exploration and reconstruction by integrating the neurosurgical, physical medicine and rehabilitation, neurologic, and plastic surgical services. (2) Secondary residual deformities—most notably the quintessential internal rotation and adduction deformity of the upper extremity—arise from both prolonged conservative management and failed surgical treatment; however, an effective armamentarium of reconstructive options (tendon transfers, muscle releases, neurotizations, and free muscle flap transplantations) has evolved to markedly improve the functional status of these patients. (3) Innovative reconstructive approaches, including nerve grafting, intraplexal and extraplexal neurolysis, and nerve transfers, should be well planned and applied for maximal functional recovery of the extremity. Priorities for the restoration of hand function, elbow flexion, and shoulder abduction should be the goal.