Osteolysis of the pelvis is a common and well-recognized complication associated with total hip arthroplasty. The diagnosis and treatment of osteolysis of the pelvis is a challenging and controversial problem. Osteolysis of the pelvis often is asymptomatic and does not present with symptoms until considerable bone loss and loosening of the acetabular socket occur. Radiographs are the most common way to detect and monitor osteolysis around an implant. However, lesions viewed radiographically usually are underestimations of the lesions found intraoperatively. Moreover, some advocate computed tomography scanning to evaluate these lesions. The indications for treatment of osteolysis with cemented acetabular components are defined more clearly than with a cementless component. If the cemented or cementless acetabular component is loose, then revision is necessary. However, it is less clear when to intervene surgically with a well-fixed cup with osteolysis. Many early reports advocated the removal of a well-fixed socket during revision surgery for osteolysis and polyethylene wear. However, the removal of a well-fixed socket has the potential for significant damage and loss of the surrounding bone resulting in loss of integrity of a column or pelvic discontinuity, which may compromise placing another acetabular component. Recently, a new treatment strategy of retaining a well-fixed socket, exchanging the liner, and grafting lesions has proven successful. Without the removal of the acetabular shell, different techniques are needed to graft the osteolytic lesions. Osteolysis is a difficult problem; however, with radiographic surveillance to monitor patients for lesions, proper indications, and good surgical techniques, the treatment of osteolysis of the pelvis can result in a well-functioning total hip arthroplasty.