Mallet injuries are the result of incompetence of the terminal tendon. Most acute mallet fingers can be treated by continuous splinting of the distal interphalangeal (DIP) joint in extension for 5-6 weeks. Fracture dislocations require open reduction and internal fixation. Treatment of chronic mallet injuries must be individualized. If there is a flexible swan neck deformity, spiral oblique ligament reconstruction is indicated. For a fixed contracture, DIP joint arthrodesis is preferred. Profundus avulsion injuries, or jersey finger, seen within 10 days of injury require operative reattachment of the profundus tendon. Treatment of avulsions more than 10-14 days after injury must be individualized and depends on location of the stump (palm vs. digit), time from injury, passive mobility of the digit, and individual functional demands. Chronic avulsions, where the stump is distal to the proximal interphalangeal joint can often be advanced secondarily. Other options include no treatment, stump excision with or without DIP joint arthrodesis, or flexor tendon reconstruction with a free graft. Level of Evidence: Therapeutic study, Level V (Expert opinion).