While most neonatal obstetrical brachial plexus injuries improve spontaneously, some require surgical intervention. It is critical for providers to recognize, diagnose, and treat these pathologies in a timely fashion to optimize the long-term function of affected muscles. In this chapter, we briefly discuss the presentation, natural history, and operative nerve repairs. As an example, we provide a cadaver dissection video of the spinal accessory to suprascapular nerve transfer via posterior approach to restore shoulder abduction and external rotation.