&NA;The trapezius is one of the major scapular‐stabilizing muscles. It is composed of 3 functional components and contributes to coordinated scapulothoracic rhythm by elevating, rotating, and retracting the scapula. The muscle is primarily innervated by the spinal accessory nerve, or cranial nerve XI. The superficial course of the spinal accessory nerve in the posterior cervical triangle makes it susceptible to iatrogenic or penetrating trauma. Idiopathic and traction injuries are also seen.Paralysis and/or dysfunction of the trapezius may result in pain, stiffness, weakness, and altered mechanics of the shoulder girdle. The scapula translates laterally and rotates downward, resulting in pronounced drooping of the shoulder. Patients typically present with an asymmetric neckline, winging of the scapula, and weakness of forward elevation and abduction. A complete clinical, radiographic, and electrodiagnostic evaluation is critical to making an accurate diagnosis.When trapezius dysfunction is recognized within 1 year of a penetrating injury or iatrogenic insult, microsurgical reconstruction of the nerve may be considered. Dysfunction discovered after this time is less likely to improve with direct nerve repair or neurolysis. Active and healthy patients who fail a reasonable trial (9‐12 months) of nonoperative management are appropriate candidates for surgical reconstruction to stabilize the scapula. The modified Eden‐Lange procedure, which laterally transfers the insertions of the levator scapulae, rhomboideus minor, and rhomboideus major muscles, is the current treatment of choice for such patients. This procedure reliably relieves pain, corrects deformity, and improves function in patients with irreparable injury to the spinal accessory nerve.