In planning treatment of tibial condylar fracture, the patient’s age and physical condition, associated ligament injury and accurate fracture diagnosis, such as presence and degree of separatiori of split fragment, type of fracture and the severity of comminution must be considered. For accurate diagnosis, many kinds of methods including simple X-ray, arthroscopy, arthrography and tomography can be used. In spite of these procedures, sometimes we cannot know the accurate fracture morphology. The computed tomography(CT) has many advantages over other diagnostic methods. The application of CT in the evaluation of patients with spinal and pelvic fractures has been established, but rarely has its usefulness been noted in tibial condylar fracture. We thought that in assessing tibial condylar fracture, CT is more useful and accurate than conventional radiography. From March 1985 to August 1986, we took 17 patients(18 cases) of tibial condylar CT and were convinced with that it is a good diagnostic method. The results are as follows: l. In 5 cases, we could find a new fracture on CT film, which was impossible to be detected on simple X-ray. 2. In 7 cases, the fracture classification by plain X-rays was changed after CT check-up. 3. We could make the decision of treatment methods easily through more realistic classification and better recognition of split and comminution. 4. Proper approach could be done by understanding the accurate fracture size and localization.