OBJECTIVE The purpose of this study was to evaluate the treatment of patients with Mason type III radial head fracture with and without elbow dislocation by open reduction with internal fixation, collateral ligament repair, and early mobilization. An additional purpose was to investigate whether there is any effect of elbow dislocation on the severity and functional outcome. METHODS Twenty-five patients were treated with open reduction with internal fixation using low-profile miniplate and screws for comminuted fracture of the radial head. Eighteen fractures were Mason type III, and 7 fractures were Mason type III with elbow dislocation. There were 5 women and 20 men with a mean age of 34 years. The mean follow-up time was 27 months. Patients were reviewed for functional ability, physical examination, and radiographic assessment. RESULTS The mean functional index in Mason type III fracture and Mason type III fracture with elbow dislocation was 87 for both groups. The mean range of motion at the elbow joint was calculated as 5 degrees extension to 136 degrees flexion for Mason type III and 7 degrees extension to 133 degrees flexion for Mason type III with elbow dislocation. The mean pronation and supination for all patients were 74 degrees and 67 degrees , respectively. CONCLUSIONS Selected Mason III radial head fractures and fracture dislocations could be stabilized satisfactorily with internal fixation. Meticulous surgical technique, combined with rigid internal fixation, can allow early motion of the forearm and elbow after fixation of Mason type III radial head fractures with and without elbow dislocation and ligamentous injury. We believe there is still a role for prosthetic replacement in comminuted Mason III radial head fractures that cannot reliably be treated with open reduction and internal fixation. METHODS Prognostic II.