Sinonasal lymphoepithelial carcinoma (LEC) is an extremely rare malignancy that shares some characteristics with nasopharyngeal carcinoma. In Asian populations, Epstein-Barr virus has been reported to be associated with LEC located outside of the nasopharynx. We report a rare case of sinonasal LEC with locoregional extension (brain and orbit). A 39-year-old Malay male initially presented with profound blurring of vision on the left eye (LE) and proptosis, followed by nasal symptoms of anosmia. Clinical examination revealed that the LE visual acuity was 6/36, with reduced optic nerve function with normal funduscopic findings, non-axial proptosis, and minimal limitation of extraocular movement. Subsequently, his vision worsened with perception of light in three days. Radioimaging studies showed soft tissue lesion at the ethmoid sinus with extensive local and intracranial extension. Microscopic analysis and immunohistochemistry confirmed the diagnosis of LEC. The patient was given induction chemotherapy followed by concurrent chemoradiotherapy with weekly intravenous cisplatin. Upon completing the fourth cycle of chemotherapy, the patient's ocular symptoms and general conditions worsened. Repeated imaging showed worsening intracranial extension with cerebral and cerebellar edema, and the patient succumbed to death. Sinonasal LEC is a rare malignant tumor with little mention in the literature. This case was reported to highlight the importance of a high index of suspicion for acute ocular symptoms with mass.