Total hip arthroplasty is one of the major operations in orthopedics. Pain that occur after this operation can be divided into two major categories according to the causes; Regional complications (extra-articular complications) and Causes of pain after THA in relation to prosthesis itself (articular complication) Different items of causes of pain after total hip replacement under major categories are completely and separately discussed.Good patient selection before taking the decision of total hip arthroplasty is very essential to decrease the incidence of pain postoperative.