Acute pulmonary edema during anesthesia and operation is not common. We have recently experienced a case of acute pulmonary edema in a 13 year old girl which developed during anesthesia and operation for her fractured radial head. No specific cause could be found. She didn't have any known cardiopulmonary disease, and responded well to vigorous therapy, but hypoxic brain damage resulted. Her semicomatose state lasted about 40days, and she then recovered slowly and completely in several months.