Cholesterol granuloma is an uncommon inflammatory lesion whose etiology is still unclear. It is thought to originate from blood accumulation in a pneumatized space, probably after bleeding. The most frequent site is the petrous apex of the temporal bone, whilst it is very uncommon in the paranasal sinuses. We present a clinical case of an 80-year-old female patient with intense frontal headache and diplopia who underwent a neuro-navigated endoscopic sinus surgery. The histological diagnosis was a cholesterol granuloma of the frontal sinus, contaminated by Aspergillus Fumigatus hyphae. Cholesterol granuloma of the frontal sinus is a rare finding in clinical practice, but it should be taken into account in the diagnostic path in presence of rapidly increasing sight alterations and headache, even without rhinological symptoms.