The anterior superior iliac spine (abbreviated: ASIS) is a bony projection of the iliac bone and an important landmark of surface anatomy. It refers to the anterior extremity of the iliac crest of the pelvis, which provides attachment for the inguinal ligament, and the sartorius muscle. The tensor fasciae latae muscle attaches about 5 cm away at the iliac tubercle.
The anterior superior iliac spine provides a clue in identifying some other clinical landmarks, including:
McBurney's point Roser-Nélaton line True leg length (see unequal leg length)