Tonsillectomy is one of the most common procedures in Otolaryngologic departments and a variety of hemostatic agents and techniques have been used in an attempt to reduce intraoperative blood loss and postoperative bleeding in tonsillectomies. The efficacy of most of these substances and techniques has been judged primarily from clinical impressions. Because of the paucity of prospective randomized studies, this study was conducted using the patients as their own control, Twenty-four patients were injected before tonsillectomy with normal saline solution in one tonsil and 1 : 100,000 epinephrine in the other. The blood loss, time of dissection, postoperative bleeding and cardiac manifestation were recorded separately for each tonsil. The tonsils injected with epinephrine had a significant reduction in blood loss and dissection time when compared with those injected with normal saline. There was no difference in incidence of postoperative hemorrhage. Cardiac manifestations of epinephrine were sligh increases in blood pressure and pulse rate. There were minimal and transient. This study demonstrates that epinephrine is useful in reducing hemorrhage during tonsillectomy and can be used safely with the appropriate general anesthetics.