Background: Immunoglobulin G4-related disease is a rare systemic inflammatory disease that can lead to vascular manifestations such as periarteritis. Case Presentation: A 41-year-old man with stress angina was referred for coronary bypass surgery due to triple vessel coronary disease. Conclusions: Operative findings revealed significant adhesions and dense pericoronary and periaortic thickening, also involving the left internal mammary artery. The IgG4-associated disease was confirmed by aortic pathology. The stress angina subsequently improved with the initiation of treatment with prednisone and rituximab.