Immunoglobulin G4 (IgG4)-related disease is a systemic inflammatory disorder that was first described in patients with autoimmune pancreatitis. Although IgG4-related disease is thought to involve the cardiovascular system, case reports describing coronary artery involvement are relatively rare. We describe a patient who was previously diagnosed with autoimmune pancreatitis and found to have coronary periarteritis and luminal narrowing. After the initiation of steroid treatment, the patient's coronary periarteritis and luminal stenosis were both ameliorated with an improvement in the serum IgG4 concentration. The present findings collectively suggest that IgG4-related immuno-inflammation may have a role in the development of coronary periarteritis and luminal atherosclerosis.