Untreated hip joint in cerebral palsy children leads to subluxation or dislocation caused by muscle imbalance often with associated painful arthritis. The very strong hip joint flexors and adductors muscles overpower the abductors and extensors muscles, moving the hip joint's rotation center to shift from center of the femoral head to the lesser trochanter. The forces gradually change the shape of the acetabulum, which becomes more elliptical. Between 1994 and 2000, 136 cerebral palsy children were treated by multilevel soft tissue surgery. Among them 95 children required surgical interventions for hip problems. In 18 cases (7 girls, 11 boys) with average adduction of 10 degrees and migration index over 60%, osteotomy of proximal femur (varus and derotation osteotomy) combine with Dega pelvic osteotomy was performed. Mean age at the time of surgery was 11.2 years. The study was based on clinical examination, parents' questionnaire and radiological findings (mean follow up 8 years). The functional improvement was observed. Correction of the position of femoral head into acetabulum allowed for sufficient abduction of the leg with mean increase of 18 degrees. In ambulatory patients, gait pattern had change to less energy. In non-ambulatory patients improved ability of perineal care. Migration index decreased to an average of 25%. Hip pain decreased in all. The unsatisfactory results were noted in two cases, redislocation. Dega's acetabular osteotomy allows for correction deficiency of the acetabulum with a good coverage of femoral head. With a properly planned approach, bone surgery can bring good clinical and functional results.