The records of 38 consecutive patients (38 fractures) who underwent treatment for distal unicondylar fractures of the proximal phalanx were reviewed to evaluate fracture characteristics, mechanism of injury, treatment options, and functional outcomes. Four classes of fracture pattern were defined radiographically. Most fractures occurred during ball sports and involved an axial splitting of extended digits, with the condyle closet to the midline of the hand fracturing most commonly. We believed that the fracture occurred as a result of tension loading due to a distraction force from the collateral ligament. All fractures healed. Follow-up examination averaged 3 years. Five of seven nondisplaced fractures treated with splinting and four of ten displaced fractures treated with reduction and single Kirschner wire fixation displaced. Fractures treated with multiple Kirschner wire fixation had the best final joint motion. Class IV fractures with a small palmar coronal fragment had the poorest final motion. A short period of post-operative immobilization did not adversely affect final proximal interphalangeal joint motion. We recommend multiple Kirschner wire or miniscrew fixation of these fractures as the most predictable method of treatment. Final proximal interphalangeal joint motion is not uniformly excellent in patients with these fractures.