The trochanteric fracture occurs through the wide metaphyseal area, giving it high potential for healing and results in low incidence of non union. Even in the treatment of unstable trochanteric fracture, the results are relatively good with the advancement of fixation devices and reduction methods. The authors experienced 10 cases of non-union of trochanteric fractures from 1975 to 1984 and followed them up for more than 1 year at Orthopaedic department of National Medical Center. The results are as follows, l. Of reduction methods in primary operation, anatomical reduction was performed in 6 cases, medialization in 2 cases. Of fixation devices, compression hip screw was used in 2 cases, Jewett nail in 3 cases and others in 3 cases. 2. The probable causes of non-union were fixation failure in 6 cases, inadequate immobilization in 2 cases, infection in 2 cases and trauma in 1 case. The other 2 cases were not treated. 3. In secondary operation, anatomical reduction was performed in 3 cases, valgus reduction in 3 cases and valgus with medialization in 2 cases. Of fixation devices, compression hip screw was used in 3 cases, Judet plate in 3 cases and Jewett nail in Z cases. 4. The time interval between the last operation and bony union was 4.2 months clinically and 6.6 months radiologically in average. 5. During follow-up, hip pain was noted in 2 cases. Limited range of motion of hip and knee in 4 cases.