IgG4-related disease (IgG4-RD) is a fibro-inflammatory condition characterized by lymphoplasmacytic infiltrates rich in IgG4-positive plasma cells, often with elevated serum IgG4. Multiple organs may be affected. Coronary arteritis may be one form of fatal involvement in IgG4-RD. IgG4-RD can manifest as periocular lesions, called IgG4-related ophthalmic disease (IgG4-ROD). Here, the authors describe a patient with asymptomatic coronary arteritis detected after the diagnosis of IgG4-ROD. A 58-year-old male complained of eyelid swelling and diplopia without systemic symptoms. Swelling of bilateral lacrimal glands and infraorbital nerves, high serum IgG4 levels, and histopathology of lacrimal gland tissue fulfilled diagnostic criteria for IgG4-ROD. After diagnosis, systemic and coronary CT showed coronary lesions and coronary artery stenosis. After prednisolone at 40 mg/day was administered, swelling of the lacrimal glands, diplopia, and coronary lesions improved. This case emphasizes the importance of systemic screening, even if initial symptoms are solely associated with periocular regions.