OBJECTIVE This study was designed to determine surgical indications in tibial plateau fractures and to evaluate the effect of surgical treatment on the outcome. METHODS Forty patients (12 women, 28 men; mean age 39 years; range 18 to 75 years) underwent surgical treatment for 41 tibial plateau fractures. Final evaluations included 37 patients (38 knees). Fractures were classified according to the Schatzker's system, being type 1 (11 fractures), type 2 (11), type 3 (1), type 4 (6), type 5 (5), and type 6 (7). The indications for surgery were defined as the presence of depression, displacement, and instability being greater than 4 mm, 10 mm, and 10 degrees, respectively. The mean follow-up was 35.8 months (range 6 to 107 months). RESULTS Clinical results were assessed using the Rasmussen criteria. Successful results accounted for 86.8%. The results were excellent, good, moderate, and poor in 14 knees (36.8%), 19 knees (50%), three knees (7.9%), and 2 knees (5.3%), respectively. Postoperative complications included deep (2 patients) and superficial (2 patients) infections, malunion in two patients, arthrofibrosis in three patients, and myositis ossificans in one patient. Radiologic evaluations were based on the Resnic and Niwayama's system, which showed successful outcome in 73.6%. The results were excellent in 11 knees (28.9%), good in 17 knees (44.7%), moderate in six knees (15.8%), and fair in four knees (10.6%). CONCLUSIONS In order to achieve satisfactory results in tibial plateau fractures that meet surgical indications including depression (>4 mm), displacement (>10 mm), and instability (>10 degrees), special attention should be given to obtain a rigid osteosynthesis with early mobilization and to avoid weight-bearing until bone healing is completed.