The purpose of this study was to compare postoperative administration of bupivacaine, a long-acting local anesthetic, with lidocaine, a short-acting local anesthetic, on pain perception and analgesic use following periodontal surgery. Ten male subjects were selected on the basis of having similar bilateral mandibular quadrants with moderate to severe periodontal disease requiring osseous surgery. The study was a matched-pair, double-blind design. Carpules of 2% xylocaine with 1:100,000 epinephrine and 0.5% bupivacaine with 1:200,000 epinephrine were wrapped in opaque tape and placed in separate coded envelopes. At the time of suturing, the quadrant was injected with one Carpule from one envelope. The Carpules from the second envelope were saved for the second surgery, which took place approximately one month later. Subjects were given standardized postoperative instructions and prescriptions for Peridex and Tylenol #3. They were told not to take the analgesic unless pain or discomfort occurred. They were given a self-administered questionnaire and asked to assess pain and/or discomfort 2, 4, 6, 8, 10, and 12 hours after the procedure, the amount of analgesic taken, and time when complete sensation returned. Results showed that the quadrants which received lidocaine maintained postoperative anesthesia an average of 2.47 hours while the Marcaine quadrants had a significantly longer duration of 5.62 hours. A large intra- and intersubject variability was noted in the amount of analgesic taken. The lidocaine group reported an average of 3.70 tablets versus a significantly smaller amount for the bupivacaine group of 1.60 tablets. Throughout all time intervals, the bupivacaine group reported significantly less pain than the lidocaine group. When used at the end of a mandibular periodontal surgical procedure, bupivacaine provides a significantly greater duration of anesthesia, decreased postoperative pain, and a reduction of anesthesia, decreased postoperative pain, and a reduction in the amount of analgesics taken.