Developmental dysplasia of the hip (DDH) is the most common skeletal dysplasia of childhood. If left untreated, it can lead to permanent deformities and disabilities. While it was a simple acetabular deficiency at birth, the pathology may progress and lead to hip dislocation. At stages in which any physical examination finding cannot be assigned, early diagnosis is the most important factor which determined the success of the treatment. Barlow and Ortolani maneuvers have high specificity, while their sensitivity is low. The development of osseous anatomy of the hip is not mature enough in newborn period. Therefore conventional radiological imaging proves insufficient. The cartilagenous and soft tissue anatomy of the hip can be visualized directly with ultrasonographic hip imaging technique, which was developed by Graf. This method has gained widespread acceptance in the last 30 years and has become the most important diagnostic tool for early diagnosis of DDH. The need for surgical procedures decreased significantly with the widespread use of hip ultrasonography. Late term DDH complications may be reduced by the right application and interpretation of the hip ultrasonography.