PURPOSE: To discuss a novel diagnosis of post-surgical iatrogenic AICA vasospasm following eighth cranial nerve microvascular decompression as the most likely etiology for a lateral pontine infarct. OBSERVATIONS: A 49-year-old male presented with tinnitus, vertigo, binocular and monocular diplopia following left occipital decompressive craniectomy and microvascular decompression of cranial nerve VIII. Magnetic resonance imaging demonstrated patent vasculature with evolution of a subacute infarct of the left lateral pons and middle cerebellar peduncle in the territory of the left AICA. CONCLUSIONS: We report a unique case of lateral pontine infarction without vascular occlusion acutely following surgical microvascular decompression of CN VIII, most consistent with post-surgical AICA vasospasm. This case provides a clear example of vestibular and neuro-ophthalmic complications of CN VIII microvascular decompression.