OBJECTIVE To determine whether there is a difference in the incidence of short-term complications using plain lidocaine with epinephrine versus the buffered equivalent in eyelid surgery. METHODS The authors performed a prospective, double-masked, randomized study in patients scheduled for combined upper eyelid blepharoplasty and levator advancement ptosis repair surgery with local anesthesia. Exclusion criteria included: documented allergies to lidocaine and/or epinephrine; known pregnancy; profound cognitive impairment; inability to understand the visual analog scale or the informed consent; and previous eyelid surgery. Each subject was his/her own control by using the unbuffered local anesthetic in one eye, while the buffered solution was used in the other eye. The surgeon completed a specific standardized data collection form for quantifying both intraoperative and postoperative complications, such as bleeding, bruising, and edema. Data regarding pain on injection and postoperative pain were collected from patients using a visual analog pain scale. RESULTS Thirty-nine patients were included in this study, of which 18 experienced less pain during the injection on the side where buffered lidocaine was used, 11 reported no difference, and 10 reported less pain in the eye injected with unbuffered lidocaine. Injection pain revealed a mean operative pain rating of 4.01 +/- 2.45 in the eye with buffered lidocaine versus 4.49 +/- 2.58 in the control (p = 0.06). There were no significant differences between the buffered and unbuffered lidocaine eyes as regards postoperative bleeding, swelling, or pain, and there was a trend toward less pain on injection with the buffered solution. CONCLUSIONS There were no significant differences in postoperative pain, swelling, or bleeding with the use of plain versus buffered lidocaine in eyelid surgery. There was a trend for the buffered anesthetic to cause less pain on injection.