The abdominal aorta bifurcates into the two common iliac arteries at the level of the fourth to fifth lumbar vertebrae (surface landmark is the umbilicus). The common iliac arteries are about 5–7 cm in length.

At the level of the sacroiliac joint, the common iliac arteries bifurcate to the external and the internal iliac arteries.

The external iliac artery runs along the medial border of the psoas muscle and goes underneath the inguinal ligament to become the common femoral artery. It gives two major branches: the inferior epigastric artery, just above the inguinal ligament, and the deep iliac circumflex artery, which arises from the lateral aspect of the external iliac artery opposite the inferior epigastric artery.

The internal iliac artery is a short and thick vessel, about 3–4 cm in length. It divides into the anterior and posterior branches at the sciatic foramen. These branches provide blood supply to the pelvic viscera, perineum, pelvic wall, and the buttocks.

The ureter crosses over the bifurcation of the common iliac artery.

The common iliac veins lie medially and posterior to the common iliac arteries. They join to form the inferior vena cava at the level of the fifth lumbar vertebra, posterior to the right common iliac artery.