Most patients with sinonasal carcinoma present to the otorhinolaryngologist with nasal symptoms. It is however uncommon for them to present with acute visual loss at first presentation. We report a case of compressive optic neuropathy secondary to sinonasal carcinoma, which presented acutely with right eye blurring of vision upon waking up. Computed tomography (CT) of the brain and orbit with contrast showed a locally invasive nasopharyngeal mass extending into the right orbit and cranial fossa. Histopathological examination revealed squamous cell sinonasal carcinoma. Her visual acuity improved with a three-day course of pulsed intravenous methylprednisolone 1 g per day, followed by a gradual tapering dose of oral prednisolone (1 mg/kg/day).