This review article describes the role of hip arthroscopy and the development of the technique over the past decade. The refinement of this technique has led to the discovery of ''new'' diseases of the hip joint. Recently, femoro-acetabular impingement (FAI) has been proposed as a source of soft tissue dysfunction, motion loss, and early osteoarthritis in the hip. Recognition of FAI is important, as failure to address this underlying pathology may lead to early onset osteoarthritis and subsequent hip replacement. The preliminary results after hip arthroscopy are described.