The authors have reviewed 14 cases of Chiari pelvic osteotomy performed in adults and followed up during more than one year. They describe the bio-mechanical properties of this procedure, and a surgical technique with some original modifications. They conclude that this operation may be contra-indicated in young women for obstetrical reasons. It is indicated in degenerative arthritis of the hip at an early stage when acetabulum is dysplasic or the femoral head subluxated.