Fifty-one patients with superior sulcus tumor of lung (Pancoast) treated over a seventeen-year period were reviewed. Musculoskeletal complaints were the presenting symptoms in forty-six patients. The clinical manifestations and diagnostic pitfalls are discussed and recommendations advanced for a thorough roentgenographic study of the thoracic inlet in any patient with persistent shoulder or neck pain, with or without brachialgia. Should any apical lung abnormality be detected, a thorough evaluation including biopsy is indicated.