The tibia is the most commonly fractured bone of all the long bones. In this age of vehicular accidents, the tibia is frequently subjected to high energy trauma. Anatomically the tibia has poor soft tissue coverage and poor blood supply. Therefore severe injury on the tibia can lead to severe complication and major disability. 41 adult patients with comminuted fracture of the tibial shaft were treated by OR/IF with D.C.P. and bone graft at the Department of Orthopedic Surgery, Kyungpook University Hospital from January 1978 to June 1986. These were analysed according to mechanism of injury, degree of comminution, timing of operation, soft tissue injury and operation time. Bone union and end results of treatment were reviewed. The results were as follows Of 41 cases, causes of injury were vehicular accident in 32 cases. 34 cases had associated injury on other part of body and average injury per case was 1.7 injuries. Based on the classification of Johner and Wruhs, the B group with butterfly fragment was 27 cases and C group was 14 cases. Among the B group, B2 was most common as 14 cases. Average union time was 18 weeks and delayed union and nonunion were 6 cases. Degree of comminution of fracture might be important fractor to bone union. According to the end result of Johner and Wruhs, excellent and good were 31, fair and poor were 10. Of the 41 cases, 10 cases had permanent disability. 4 cases had angular and rotational deformity alone and 1 case had shortening of tibia more than 1 cm, 1 case had both of them. Limited R.O.M. of ankle joint (>50%) occured in 4 cases. The post-operative infection occured in 6 cases, 3 were superficial infection but 3 cases were osteomyelitis. OR/IF with D.C.P. on comminuted tibial shaft fracture was a risk operation. Therefore proper method of treatment should be selected according to degree of comminution, timing of operation, presence or abscence of open wound and associated injury.