Background: Acute dacryoadenitis is an uncommon disease. Case: We present what we believe to be the first reported case of herpes zoster ophthalmicus with the onset of acute dacryoadenitis. Observations: A 30-year-old man complained of severe ocular pain and hyperemia in his right eye. Magnetic resonance imaging (MRI) demonstrated enlargement of the right lacrimal gland and acute dacryoadenitis was diagnosed. Two days after treatment with systemic antibiotics he developed iridocyclitis and skin lesions confined to the first division of the trigeminal nerve; therefore, herpes zoster ophthalmicus was diagnosed. Treatment with acyclovir immediately resolved the ocular pain and swelling of the upper eyelid. MRI conducted in the 4 months after the initial examination showed there was no longer enlargement of the right lacrimal gland. Conclusion: Clinicians should be aware that varicella-zoster virus may cause acute dacryoadenitis.