In human anatomy, iliac vein refers to several anatomical structures located in the pelvis: * Common iliac vein, formed by the external and internal iliac veins, drains into the inferior vena cava * Deep circumflex iliac vein, formed by the union of the venae comitantes of the deep iliac circumflex artery, and joins the external iliac vein * External iliac vein, terminates at the common iliac vein, drains the femoral vein * Internal iliac vein, terminates at the common iliac vein, drains pelvic organs and perineum