Orbital apex syndrome is a rare manifestation of Herpes Zoster Ophthalmicus. Herein we report on a case of orbital apex syndrome secondary to Herpes Zoster Ophthalmicus. A 75 year-old male complained of vision loss, conjunctival hyperemia and proptosis on the left eye, was referred to our clinic. Visual acuity was 5/10 Snellen lines and he had conjunctival hyperemia, chemosis, minimal nuclear cataract and proptosis on the left eye. A diagnosis of orbital pseudotumor was demonstrated firstly. The patient received oral and topical corticosteroids, antiinflammatory and antibiotic agents. On day 2, vesiculopustular lesions were observed, Herpes Zoster Ophthalmicus was diagnosed and corticosteroid treatment stopped, oral acyclovir treatment initiated. Two days later, total ophthalmoplegia, ptosis and significant visual loss were observed on the left. The diagnosis of orbital apex syndrome was considered and the patient commenced on an intravenous acyclovir treatment. After the improvement of acute symptoms, a tapering dose of oral cortisone treatment initiated to accelarate the recovery of ophthalmoplegia. At 5-month follow-up, ptosis and ocular motility showed improvement. VA did not significantly improve because of cataract and choroidal detachment on the left. We conclude that ophthalmoplegia secondary to Herpes Zoster Ophthalmicus responds favourably to intravenous acyclovir and steroids.