A 46-year-old man with a history of bronchial asthma and chronic sinusitis presented to our hospital with chest pain. We suspected angina evoked by epicardial coronary spasm and performed an ergonovine provocation test to diagnose coronary spastic angina (CSA). The patient also met the diagnostic criteria for eosinophilic granulomatosis with polyangiitis (EGPA) and was treated with 60 mg prednisolone (PSL) for EGPA-associated CSA. After PSL administration, eosinophils decreased, and angina attacks disappeared. However, when PSL was tapered to 12.5 mg, chest pain recurred. We administered mepolizumab subcutaneously and chest pain disappeared. Additional mepolizumab may be effective for EGPA with CSA.