Previous studies have indicated that non-steroidal anti-inflammatory drugs administered prior to oral surgery procedures are effective in reducing postoperative pain. The purpose of the present study was to compare the efficacy of medicating with ibuprofen immediately presurgically to medicating immediately postsurgically on postoperative pain associated with periodontal surgery. Sixty patients who were to undergo periodontal surgery were randomly divided into 3 groups: the I-pretreatment group received 600 mg ibuprofen immediately presurgically and placebo immediately after the surgery; the I-post-treatment group received placebo before surgery and 600 mg ibuprofen postsurgically; the placebo group received placebo at both time periods. Responses from an 8-hour pain diary completed by each subject were quantified and statistically evaluated non-parametrically. Results indicated that dosing with ibuprofen either immediately before or immediately after periodontal surgery significantly delays onset of pain as compared to placebo, with dosing after surgery demonstrating a significantly greater delay of onset of pain as compared to dosing presurgically. In addition, unlike the presurgical dosing, dosing postsurgically significantly decreases mean pain intensity for a combined 8-hour period following periodontal surgery as compared to placebo.