Hypertension is a well known finding in primary hyperparathyroidism (HPT). In the present study, systolic blood pressure (SBP) and heart rate were recorded before, during and after surgery for HPT in 101 patients (mean serum calcium 2.96 +/- 0.22 mmol/l) and compared to 91 scheduled general surgical patients matched for age, sex, duration of surgery and type of general anesthesia. The HPT patients displayed an increased mean SBP, given as mean +/- standard deviation, both before (147 +/- 28 vs 131 +/- 25 mm Hg in controls) and during surgery (142 +/- 24 vs 117 +/- 21 mm Hg in controls) as well as postoperatively (141 +/- 23 vs 118 +/- 17 mm Hg in controls, all p < 0.0001). The preoperative SBP was correlated to both the intraoperative and postoperative SBP (r = 0.59 and r = 0.61, both p < 0.00001). However, the blood pressure elevation during and after surgery was still significant (both p < 0.001) when corrected for the influence of the preoperative blood pressure level using multiple regression analysis. The heart rate was increased in the HPT subjects only in the postoperative period (88 +/- 12 vs 83 +/- 12 beats/min in controls, p < 0.007). In conclusion, the systolic blood pressure was found to be elevated both before, during and after surgery in HPT subjects when compared to a general surgical population. In the postoperative period, also the heart rate was increased in the HPT subjects. These findings suggest an increased cardiovascular response to surgical stress in HPT subjects.