The increasing trend toward performing minimally invasive neurosurgery may benefit from recent progress in using neuroendoscopic techniques to reduce trauma in patients who have undergone operations. Arterial and venous vessels, especially loops, may compress the central segment and cause hyperactive dysfunction of the nerves. Relationships of the anterior inferior cerebellar artery to the facial and vestibulocochlear nerves and the anterior inferior, and superior cerebellar arteries to the trigeminal nerve were studied. The authors report findings from an endoscopic study performed in cadaver heads via the retrosigmoid and retrolabyrinthine approaches. Arteries and veins were colored by injection of red and blue silicon rubber. The cerebellopontine angle (CPA) was examined using 2.7-mm and 4-mm-diameter rigid endoscopes at viewing angles of 0s degrees , 30s degrees , and 70s degrees . Well-known structures could be identified endoscopically without prior dissection, and the entire CPA could be explored. However, with a retrosigmoid or a retrolabyrinthine approach, the cerebellum had to be retracted to some extent to view the CPA. Moreover, wide dural exposure was required to maneuver the endoscope freely in the CPA. Use of the rigid fiberoptic endoscope is not yet superior to standard surgical techniques for approaching and exploring the CPA.