Stroke is defined as a focal neurological deficit lasting more than 24 hours. The complications related to the central nervous system after general surgery is unusual and is difficult to discover the exact causes. We are going to report a case of an unexpected cerebral infarction after a Whipple's operation. The patient was a sixty-three years old female weighing 53 Kg with a diagnosis of cancer of ampulla of Vater scheduled for a Whipple's operation under general anesthesia. Preanesthetic assessment revealed a history of hypertension and hypercholesterolemia. After surgery, she was alert but she appeared to have right hemiparesis, aphasia and right facial palsy. A brain MRI showed a cerebral infarction in the bilateral basal ganglia, left medial temporal lobe and insular cortex. The cause of the cerebral infarction in this patient was unclear. Cerebral thrombosis was first thought of, but we couldn't completely exclude other possible causes e.g., embolism etc. In cases where risk factors of a stroke were found in preoperative evaluation, it is important to correct risk factors preoperatively. Furthermore, it is necessary to prevent hypotension, keep proper hematocrit levels and temperature during an operation, and use hemocoagulase carefully in cases of patients having risk factors of thrombosis and embolism.