Tomography was useful in the preoperative assessment of twenty-one tibial-plateau fractures. It helped in classifying these fractures more precisely, information which is very important if the results of different methods of treatment are to be compared. It demonstrated clearly the extent of fracture depression or displacement, or both, as well as the site of the fracture and the extent of fracture comminution. The findings were confirmed at operation in the thirteen patients who had surgery.