AbstractContext:Agenesis of the internal carotid artery and hypoplasia of the internal carotid artery are rare congenital abnormalities, involving less than 0.01% of the general population. Congenital hypopituitarism is also a rare condition; thus, the association of the two entities is unlikely to be casual. We describe one pediatric case of agenesis of the internal carotid artery with hypopituitarism and review other known cases.Evidence Acquisition and Synthesis:In this brief clinical case seminar, we summarize the current understanding of this association based on a MEDLINE search of all peer-reviewed publications (original articles and reviews) on this topic between 1980 and 2011. We found nine other cases, mainly diagnosed during childhood. Defects of pituitary function varied among cases; in four, midline anomalies were present.Conclusion:There are two theories that are not mutually exclusive to explain the association of congenital vascular malformation and pituitary hypoplasia with hypopituitarism: the first involves hemodynamic mechanisms, and the second, complex neural-crest differentiation and/or migration disorders. Whatever the real physiopathological mechanism responsible for this condition, it could be considered as a new clinical entity.