It is well known the early diagnosis and early treatment is very important for the patient with congenital dislocation of the hip(CDH) to provide a favorable function in the whole life. However, despite screening programmes for the detection of CDH, children with dislocated hip continue to present late. While there has been general agreement as to the need for treatment of persistent acetabular dysplasia secondary to CDH, the appropriate treatment has been a matter of controversy for many years, and the surgical treatment of CDH in old children presents a more formidable technicalchallenge than in younger child. The author studied 26 cases in 23 patients of CHD aged between 6 years and 13 years at the Department of Orthopedic Surgery of Yonsei University during a 6 year period from January, 1979 to December, 1984. The aim of this study was to find out available surgical treatment for the old childhood with CDH and to assess the comparative results of age, degree of acetabular dysplasia and the station of femoral head displacement. The results of this study are are as follows; l. Among the 23 patients, female was 20 patients, male was 3 patients and 3 female patients show bilateral involvement. And among 26 cases, left hip involvement was 21 cases and right hip involvement was 5 cases. 2. Age at initial operation was 8 years and 10 months in average ranging from 6 years and 2 months to 13 years and 4 months, and average follow-up time was 3 years and 11 months ranging from 1 year 6 months to 5 years 2 months. 3. Attended type of surgery of the CDH in old childhood were 4 cases of Salter’s innominate osteotomy, 5 cases of Sutherland’s double innominate osteotomy, 5 cases of Salter’s innominate osteotomy with femoral shortening and 12 cases of Klisic procedure. 4. Age of the patient as well as degree of acetabular dysplasia and station of femoral head displacement may influence on determination of type of the surgical procedure. 5. The older the age at initial operation and the more the displacement of femoral head, the results was less favorable. 6. As in young childhood, the clinical results of treatment are invariably better than the radiological results. 7. Overall final results of leg length discrepancy was 1.0cm in length and range of leg length discrepancy differs from type to type of surgical procedure. 8. Complications developed after treatment were avascular necrosis of femoral head in one case, fracture of the ipsilateral femure in 3 cases and wound infection in 1 case.