Petrous apex cholesterol granulomas are slowly expanding lesions that clinically present with a variety of cranial nerve deficits. We present a case of a 40-year-old man with a right-sided, sudden-onset hearing loss. Apart from a 60-dB high-frequency sensorineural hearing loss in the right ear, all other neurotologic examinations were normal. Computed tomography revealed partial destruction of the right carotid canal, petrous apex, and clivus. Surgical treatment was performed via an endoscopic transnasal, trans-sphenoid approach using an image-guidance system. Postoperative magnetic resonance imaging showed a significant reduction in the size of the cholesterol granuloma and a stable hearing threshold.