Controversy exists concerning the appropriate dose of heparin needed during carotid endarterectomy. Use of high-dose heparin (100 U/kg) during carotid endarterectomy may require the use of protamine to minimize perioperative bleeding complications. At the authors' institution the use of 30 U/kg heparin for arterial reconstruction has obviated the need for protamine. A retrospective study of carotid endarterectomies performed was undertaken. Patients undergoing combined procedures with carotid endarterectomy were excluded. A total of 420 carotid endarterectomies were performed in 330 patients. All received 3000 U of heparin or less during carotid endarterectomy. Non-fatal stroke and transient neurological deficits occurred in 0.48% and 1.9%. respectively. Mortality was 0.9%. Wounds were dry in 97%, swollen in 2.5% and bloody in 0.5%. No patient received protamine. Two patients were returned to the operating room for re-exploration because of hematoma. In conclusion, the use of protamine may be safely avoided with 30 U/kg heparin, and give acceptable stroke- and minimal complication rates. © 1999, The International Society for Cardiovascular Surgery. All rights reserved.