Between 1974 and 1984, 1222 patients underwent carotid endarterectomy at a large community teaching hospital. Twenty-three (1.9%) of these patients required reexploration for hematoma at the endarterectomy site. We reviewed the records of these 23 patients with regard to the incidence of perioperative hypertension; the use of platelet-altering medication, heparin, protamine sulfate, and low molecular weight dextran; and the findings at reoperation. We also reviewed the records of 122 randomly selected patients who did not develop wound hematoma after carotid endarterectomy. The incidence of intraoperative and postoperative hypertension was significantly higher in the hematoma group than in the control group. The incidence of preoperative hypertension was not significantly different between the two groups. More hematoma patients received preoperative platelet-altering medication (43% versus 25%), and fewer received intraoperative protamine sulfate to reverse the effects of heparin (48% versus 66%), but these differences were not significant. This study emphasizes the importance of careful hemodynamic monitoring during and immediately after carotid endarterectomy.