Injuries to the latissimus dorsi and teres major muscles, while rare, are debilitating. They are seen in a variety of sports, although disproportionately in the throwing shoulder of baseball pitchers. There have been 25 case reports and 2 case series published on the nonoperative and operative management of these injuries. Latissimus dorsi and teres major muscle anatomy, function, and common injury patterns are well described in these case reports. Also well detailed are the typical patient presentation, physical examination, and imaging findings. Latissimus dorsi tendon injuries are sometimes treated operatively, whereas latissimus dorsi muscle belly or isolated teres major injuries are treated nonoperatively. Nonoperative treatment includes oral anti-inflammatories and shoulder physical therapy. A number of surgical patient positions, approaches, and fixation constructs have been described, although 2 techniques of positioning and surgical approach are used most commonly. Fixation is most often performed with suture anchors. Return-to-play timing, shoulder strength, and healing on magnetic resonance imaging are variable. No standard of care currently exists for the treatment of latissimus dorsi or teres major injuries. If treating a patient with an injury to either muscle, the clinician should be familiar with accumulated experience as reported in the published literature.