Few cases of Churg-Strauss syndrome (CSS) complicated by giant coronary aneurysms (CAs)have been reported thus far. We report a case of CSS in a 60-year-old man who underwent surgery for giant CAs, and was managed with anesthetics. The patient developed acute myocardial infarction, and was diagnosed with giant CAs in the right coronary artery (RCA, 11 cm) and circumflex artery (3 cm). The CA in RCA was communicating with the right ventricle. He had a history of pericardiectomy for pericarditis caused by the CSS and developed thrombocytopenia due to consumptive coagulopathy within the CAs. An operation, including ligation and excision of the CAs, and coronary artery bypass grafting was performed under general anesthesia and cardiopulmonary bypass. There was massive hemorrhage followed by hemodynamic instability while detaching the tight pericardial adhesion and fragile surface of the CAs. Massive transfusion was required along with inotropes administration and intraaortic balloon support. In this case, determination of the appropriate surgical timing was difficult because symptoms of the CSS became worse followed by rapid enlargement of the CAs, myocardial infarction, and thrombocytopenia. Steroids were administered for treating CSS, and the blood transfusion was sufficient. However, it was difficult to control the hemorrhage and maintain hemodynamic stability.