A 64-year-old man with fever, appetite loss, and pain in the back of the neck visited our hospital. We diagnosed him as having bacterial meningitis because of pleocytosis of the cerebrospinal fluid, and started treatment with antibiotics. Multiple cerebral infarcts were found on brain MRI. We suspected that the origin of the bacterial meningitis was infective endocarditis, and administered Cefepime and Gentamicin according to the guidelines for treatment of infective endocarditis. Three days later, he became drowsy and had myoclonus and flapping of the extremities. An electroencephalograph showed generalized periodic discharge and a triphasic wave pattern. We thought that the cause of disturbance in consciousness was Cefepime-induced encephalopathy, and stopped administration of Cefepime. A few days later, he became clear, and the myoclonus and flapping disappeared. It was difficult to distinguish between non-convulsive status epilepticus and Cefepime-induced encephalopathy. However, since stopping Cefepime treatment had made the patient clear, we diagnosed his condition as Cefepime-induced encephalopathy, which often occurs in patients with renal or liver dysfunction, or in brain infarction or meningitis, which results in blood-brain barrier disruption. Thus, care should be taken when administering Cefepime to such patients.