The clinical physicians insist in the necessity of an anatomical precise knowledge, for the success in neurochirurgical interventions during the approaching to the posterior cranial fossa. Based in previous reports, we have made an anatomical revision of the anterior inferior cerebellar artery focused to its anterior pontine and lateral pontine segments with data that may contribute to their better knowledge. This research was done by the study of 70 human brains from both sexes, collected at Sâo Paulo Medical School/ UNIFESP, Brazil, and to which them , we registred some anthropological data. The brains were inyected in its vascular system with red collored neopren latex and fixed using established anatomical techniques. The range of 1.0-1.5 mm for the external diameter of the AICA is more frecuently at right side in both sexes; in 47.4% of the Brachycephalics (BH) and in 53.1% of the Dolicho-mesocephalics (DM). At the left side and masculine sex, was observed in 45.3% and in 64.3% of feminine sex ; in 52.7% of the BH and in 53.1% of the DM. The course of the AICA at right side is ventral to abducent nerve (AN) in 68.0% in DM groups and in 69.0% in BH groups; at the left side this course was observed in 74.0% in DM and 77.0% in BH groups. The authors insist in the variability observed in the arterial patterns, when taking in consideration besides side and sex, other parameters like the cephalic index