The vast majority of tibial plateau fractures heal uneventfully, and no case series on intraarticular tibial plateau nonunions exists. The purpose of the present study was to evaluate the radiographic and clinical outcome of these nonunions following surgical treatment in a single surgeon series. Five patients with tibial plateau nonunions were treated at our institution using a specific treatment protocol consisting of open reduction and debridement, deformity correction, internal fixation including lag screws, bone graft augmentation, and selective knee joint arthrolysis. Patient outcomes were assessed using radiographs and the Knee Society questionnaire scores. Following surgical treatment of the nonunion, all healed at an average of 12.8 weeks, and average follow-up was 44 months. Preoperative coronal plane deformity was corrected in all patients. The final knee motion arc averaged 120 degrees postoperatively. Both the pain and function subscales of the Knee Society Rating scale improved significantly. Four of the five returned to their normal pre-injury activities, but two patients required total knee arthroplasty which was performed successfully after healing of the nonunion. With meticulous surgical technique and a standard protocol, healing may be reliably achieved. Arthrosis occurs frequently, and may occur primarily at the time of injury or from chronic alteration of intraarticular contact forces secondary to development of a nonunion.