Abstract:Two‐hundred and one outpatients with postoperative pain following oral surgery were randomly assigned, on a double‐blind basis, a single oral dose of diflunisal (250, 500, or 1000 mg), aspirin (650 mg), or placebo. Using a self‐rating record, the subjects rated their pain and its relief hourly for 12 hours after medication. Measures of peak and total analgesia were derived from the patients' subjective reports. Diflunisal 250 and 1000 mg were significantly superior to aspirin for every measure of total and peak analgesia; the 500‐mg diflunisal dose was significantly superior to aspirin for measures of total analgesia only. All doses of diflunisal were significantly superior to aspirin and placebo at each hour from hour 3 through hour 12. Approximately 60 per cent of the patients treated with diflunisal completed the 12‐hour observation period without the need for additional analgesic therapy. Adverse effects were mild and transitory and occurred in less than 10 per cent of the