Informed consent is required for not only operative procedures but also anesthesia. One hundred and sixty-two patients, including those in a control group, were interviewed between the 3rd and 10th days after operations. An information sheet describes the anesthetic management and complications (possibilities of teeth damage, hoarseness and sore throat) in a simple style. This survey showed that those who had received the information sheet before operation showed significantly deeper understanding of anesthesia (56.2%) compared with those who had not received the information sheet (40.3%) (P < 0.05). The information sheet did not cause or increase anxiety about anesthesia. Those who had anxiety about anesthesia before the operation needed detailed printed information (63.8%) compared with those without anxiety (36.6%) (P < 0.01). An information sheet describing the anesthetic management and complications is useful for obtaining informed consent.