The causes of hip pain are variable, and, due to its size and deep position, complete physical examination is often difficult. In the past, ultrasonography (US) for the hip was mainly performed in order to rule out developmental hip dysplasia in infants or for evaluation of joint effusion. Now, however, US of the hip has been widely accepted as a useful modality in patients with hip pain and is commonly used in both adults and children. Joint effusion, bursitis, tendinosis or tendon tear, and acetabular labral tear can be main targets. Dynamic study for snapping hip is another unique advantage of US. In addition, US is very useful for guided procedures - aspiration, biopsy, or injection. In this review, the authors will discuss US findings of these common lesions with a brief review of anatomy.