From 1975 to 1984, 134 consecutive lateral tibial plateau fractures were treated as part of this prospective study. Eighty-six fractures (64%) were followed until union, with an average follow-up period of 22.7 months. The two aims of this study were: First, to analyze the results of operative and nonoperative therapy in each fracture type, and second, to evaluate the effect of early weight bearing in a cast brace in both types of treatment. All lateral tibial plateau fractures with greater than 5 mm depression or displacement were treated operatively. Forty-four patients were treated operatively and 42 patients nonoperatively. All patients were treated with early range of motion and weight bearing in a cast brace. Fractures were initially classified using Hohl's classification system. Overall, 95% of the patients with Type I, II, or V fractures had satisfactory results, as opposed to only 70% of patients with Type III fractures. Of the Type III fractures, 83% treated operatively had satisfactory results compared with 53% treated nonoperatively. Moreover, early weight bearing did not produce further depression greater than 2 mm.