Introduccion: la arteria trigeminal persistente (ATP) es la mas comun de las anastomosis embriologicas entre la arteria carotida interna (ACI) y el sistema vertebro-basilar, que puede ser encontrada en la edad adulta. Suele ser encontrada como un hallazgo incidental en estudios de la vasculatura cerebral. Caso clinico: paciente de 71 anos de edad, hipertenso arterial en tratamiento regular, quien desde hacia tres anos presentaba cefalea de leve intensidad, asociada a vertigos ocasionales y disestesias del lado derecho corporal. Examen neurologico normal. En resonancia magnetica cerebral se observo imagen con vacio de senal en cisterna prepontina. Angiografia cerebral con contraste permitio observar arteria aberrante que comunicaba el asa posterior del segmento intracavernoso de la ACI con la arteria basilar (AB). Conclusion: la deteccion de las anomalias vasculares y en especial de la ATP es de gran importancia en el planeamiento preoperatorio para las lesiones de fosa craneal media, region selar y paraselar. La ATP se puede asociar a algunas alteraciones neurologicas o a otras variantes anatomicas vasculares. Rev.cienc.biomed. 2013;4(1):147-151 PALABRAS CLAVES Neurocirugia; Angiografia cerebral; Anatomia; Sistema Nervioso Central. SUMMARY Introduction: Persistent trigeminal artery (PTA) is the most common of the embryologic anastomoses between internal carotid artery (ICA) and the vertebro-basilar system, which can be found in the adult age. It usually is found as an incidental discovery in studies of cerebral vasculature. Clinical case: It is presented a 71 years-old patient with arterial hypertension in regular treatment, who had been presented headache of mild intensity associated to occasional vertigos and paresthesias in the right corporal side since three years ago. Neurological exam was normal. In the cerebral magnetic resonance, an image with empty of signal was observed in the prepontine cistern. The cerebral angiography with contrast allowed observing aberrant artery that connected the posterior loop of theintracavernous segment of the ICA with the basilar artery (BA). Conclusion: The detection of vascular anomalies and especially of the PTA is very important in the preoperative planning for the injuries of middle cranial fossa, sellar and parasellar region. The PTA can be associated to some neurological disorders or to other anatomical vascular variations. Rev.cienc.biomed. 2013;4(1):147-151 KEYWORDS Neurosurgery; Cerebral Angiography; Anatomy; Central nervous system.