To report an unusual absent right common carotid artery with embryological and clinical emphasis.

A 63-year-old female with a multilobulated anterior communicating artery saccular aneurysm was referred to our center for definite treatment. An analysis of her carotid system on CTA and DSA with 3D modeling was performed to assess the embryology of an absent right common carotid and its association with aneurysm development.

Cerebral angiogram demonstrated an absent right common carotid artery and separate origin of the internal and external right carotid arteries arising from the brachiocephalic trunk.

Absence of the common carotid artery is an uncommon anatomical variant, usually asymptomatic and commonly associated with other vascular abnormalities. It is important to be familiar with the association between this anatomical variant given its hemodynamic stress, high risk of stroke, and aneurysm formation.