Hip disarticulation is usually elected for malignant bony and soft tissue tumors below the lesser trochanter of the femur. The operation is performed with the patient in a posterolateral position; in the first phase of the procedure the surgeon stands anterior to the patient. After incision of the skin and division of the femoral vessels and nerve, muscles of the anterior thigh are transected off the pelvic bone from lateral to medial starting with the sartorius and finishing with the adductor magnus. Muscles are divided at their origin except for the iliopsoas and obturator externus which are divided at their insertion on the lesser trochanter of the femur. The quadratus femoris muscle is identified and preserved, then the flexor muscles are transected at their site of origin from the ischial tuberosity. During the next phase the surgeon is posterior to the patient, and the pelvis is rotated from the posterolateral to the anterolateral position. After completion of the skin incision, the gluteal fascia, tensor fascia lata, and the gluteus maximus muscles are divided and dissected free of their posterior attachments to expose the muscles inserting by way of a common tendon onto the greater trochanter. These muscles are then transected at their insertion on the bone. The posterior aspect of the joint capsule is then exposed and transected. Finally, the sciatic nerve is divided and allowed to retract beneath the piriformis muscle. To close the wound the preserved muscles are approximated over the joint capsule and the gluteal fascia secured to the inguinal ligament over suction drains. The skin is closed with interrupted sutures.