Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The posterior cutaneous nerve of the thigh (also called the posterior femoral cutaneous nerve) provides innervation to the skin of the posterior surface of the thigh and leg, as well as to the skin of the perineum. The posterior cutaneous nerve of the thigh is a nerve from the sacral plexus. It arises partly from the dorsal divisions of the first and second, and from the ventral divisions of the second and third sacral nerves, and issues from the pelvis through the greater sciatic foramen below the piriformis muscle. It then descends beneath the gluteus maximus with the inferior gluteal artery, and runs down the back of the thigh beneath the fascia lata, and over the long head of the biceps femoris to the back of the knee; here it pierces the deep fascia and accompanies the small saphenous vein to about the middle of the back of the leg, its terminal twigs communicating with the sural nerve.