The term "developmental dysplasia or dislocation of the hip" (DDH) refers to the complete spectrum of abnormalities involving the growing hip, with varied expression from dysplasia to subluxation to dislocation of the hip joint. Unlike the term "congenital dysplasia or dislocation of the hip," DDH is not restricted to congenital problems but also includes developmental problems of the hip. It is important to diagnose these conditions early to improve the results of treat- ment, decrease the risk of complications, and favorably alter the natural history. Careful history taking and physical examination in conjunction with advances in imaging techniques, such as ultrasonography, have increased the ability to diagnose and manage DDH. Use of the Pavlik harness has become the mainstay of initial treatment for the infant who has not yet begun to stand. If stable reduction cannot be obtained after 2 weeks of treatment with the Pavlik harness, alternative treatment, such as examination of the hip under general anesthesia with possible closed reduction, is indicated. If concentric reduction of the hip cannot be obtained, surgical reduction of the dislocated hip is the next step. Toward the end of the first year of life, the toddlerTs ability to stand and bear weight on the lower extremities, as well as the progressive adaptations and soft- tissue contractures associated with the dislocated hip, preclude use of the Pavlik harness.