To investigate blood pressure and pulse rate responses to dental surgery, 21 patients 18 to 73 years of age (mean age, 42±4 years) who visited our hospital for tooth extraction were studied. Before dental treatment, the patients underwent a mental arithmetic stress test, electrocardiography, and an anxiety evaluation with the State-Trait Anxiety Inventory. Baseline blood pressure and pulse rate were 118±4/70±3mmHg and 69±2 beats/min, respectively. Blood pressure rose by 24±3/17±2mmHg during the mental stress test, and the magnitude of the rise in systolic blood pressure was significantly correlated with age (r=0.81, p<0.001) and baseline blood pressure (r=0.56, p<0.01). After the topical injection of local anesthetic containing 1:80, 000 epinephrine, a transient increase in systolic blood pressure was observed. The maximum blood pressure and pulse rate increases during dental surgery were 24±4/13 ±2mmHg and 17±3 beats/min, respectively. Similarly, the rate pressure productincreased from 8, 196 ±486 to 11, 802±682. The magnitude of the blood pressure increase during dental surgery was not correlated with age, sex, family history of hypertension, baseline blood pressure, anxiety score, or response to mental stress. On the other hand, when the subjects were divided into two subgroups according to the blood pressure response during dental surgery, the larger response group (increase in mean blood pressure greater than 15mmHg, n=9) required a significantly larger dose of local anesthetic than did the smaller response group. The number of cases of pericoronitis of the third molar tended to be greater in the larger response group. These results indicate that an increase in blood pressure during dental surgery cannot be predicted on the basis of baseline blood pressure or the response to mental stress, but is related to the cause of tooth extraction and the volume of local anesthetics required to control the pain. (Hypertens Res 1996; 19: 189-194)