Displaced fractures of the olecranon in adults were analyzed for pain, function, range of motion, and roentgenographic appearance. With one exception, the 38 transverse or oblique fractures were treated by reduction and internal fixation. Results were best in the group treated by screw plus wire in combination (average rating, 17.7 points). Other ratings averaged 17.2 for the intramedullary screw, 16.8 for figure-of-eight wire, and 16.7 for Arbeitsgemeinschaft fur osteosynthesefragen (AO) tension-band wire. Factors associated with poorer results included postoperative displacement or malreduction greater than or equal to 2 mm and articular involvement greater than or equal to 60%. Symptomatic metal prominence was particularly common after AO tension-band wiring, occurring in 80%. All seven comminuted fractures were treated by primary excision. The one comminuted fracture with greater than or equal to 60% articular involvement that was treated by excision had a poor result because of instability.