Immunoglobulin G4-related disease (IgG4-RD) is an autoimmune disease characterized by elevated serum IgG4 levels. It has the potential to affect multiple organs. Despite the diverse manifestations of IgG4-RD, the association with coronary artery disease (CAD) remains poorly understood due to limited evidence. We report the case of a 52-year-old male patient who exhibited typical angina upon exertion, accompanied by elevated serum IgG4 levels. Coronary computed tomographic angiography (CCTA) revealed the presence of pseudotumor formations surrounding and aneurysm changes affecting all coronary arteries, consistent with IgG4-RD. The patient was treated with prednisolone and azathioprine, with the possibility of additional rituximab therapy if symptomatology failed to improve. This case sheds light on the rare occurrence of IgG4-RD with coronary artery involvement and underscores the importance of recognizing this unique clinical entity for appropriate management and further research.