[1]: 472 Each posterior communicating artery is situated within the interpeduncular cistern, superolateral to the pituitary gland.

[2]: 450  Each are is situated upon the medial surface of the ipsilateral cerebral peduncle[1]: 477  and adjacent to the anterior perforated substance.

The development of the posterior cerebral artery (PCA) in the fetal brain occurs relatively late and arises from the fusion of several embryonic vessels near the caudal end of the posterior communicating artery.

The PCA begins as a continuation of the posterior communicating artery in 70-90% of fetuses with the remainder of PCAs having a basilar origin.

This provides redundancies or collaterals in the cerebral circulation so that, if one system is blocked or narrowed, the other can take over.