We report the case of a 72-year-old male who presented with the complaints of muscular pain and weakness. The patient showed marked eosinophilia, elevated levels of myogenic enzymes and pathological abnormalities including eosinophil infiltration obtained from the muscle biopsy. Based on these findings, the patient was diagnosed with eosinophilic myositis. During follow-up, left ventricular wall motion abnormalities with transient electrocardiographic abnormalities were identified; these were believed to be concurrent with eosinophilic myocarditis. Further, notable complications included cardiogenic cerebral embolism. Eosinophilic myositis has been found to cause a wide spectrum of complications. Our findings indicate that in cases of suspected eosinophilic myositis, it is crucial to identify myocarditis immediately and to select an anticoagulant therapy to prevent cerebral embolism.