The relief of pain after extraction of a mandibular third molar by two analgesics, rimazolium and acetylsalicylic acid (ASA) was studied in three groups of patients, who received either of these analgesics or a placebo. A questionnaire and careful instructions on its use were given to the patients. ASA had a better effect than both rimazolium and placebo. The results are discussed with regard to differences between analgesics with or without anti-inflammatory properties.