PURPOSE: The purpose is to analyze the efficacy of the MR images in the diagnosis and the treatment of the tibial plateau fracture, by comparing the amount of depression in the plain radiograph and in the MR images. MATERIALS AND METHODS: Both the MRI and the plain radiograph were performed in 14 patients from 1997 to March 2001. The Schatzker-fracture type and the amount of joint depression were measured and compared in the plain radiograph and the MR images. RESULT: In the Schatzker's classification, both type I and II were largest in number. The average amount of joint depression was measured as 1.8 mm by plain radiograph and 5.5 mm by MRI, so the difference was measured as 3.7 mm. CONCLUSION: In some cases the joint depressions were more than 3 mm by measuring in the MRI, even though the amount of joint depressions were much less by measuring in the plain radiograph. After measuring with MRI, the indication of the surgery may be expanded. In conclusion, as MRI in the tibial palteau fractures can give precise information of the amount and the position, it may help the prediction of the surgical indication and prognosis.