Developmental dysplasia of the hip (DDH) is the presence of acetabular femoral head in a different place without normal relationship at birth. The etiology is unknown, however related to many factors. DDH should be diagnosed and treated in time. When it is detected in the early stages it can be treated successfully with conservative methods. As well as history taking and physical examination, radiological examinations have an important role in the diagnosis of DDH. Ultrasound is a safe method for monitoring DDH and is required for early diagnosis and treatment of hip dislocation. Imaging techniques such as radiography, computed tomography, magnetic resonance are also used for diagnosis. A subluxated or dislocated hip of DDH treatment differs with the patient’s age but should be individualized. The success of treatment with a Pavlik harness application is closely related to age. While the success rate is 90% in the first 7 weeks, it lowers considerably after 6-9 months of age. Early diagnosis is very important for DDH. At this point, family physicians, pediatricians, midwives and mothers have a great role.