The clinical effect of Rheumapax ® and placebo on postoperative complications after surgical removal of the impacted mandibular third molar has been evaluated in a controlled clinical trial. The investigation included 66 patients in two treatment groups, 32 patients being given Rheumapax and 34 placebo. Hematological tests performed before and 10 days after the operation revealed no adverse reactions. There was a significant reduction of postoperative pain and trismus with Rheumapax in addition to a favorable, though nonsignificant, effect on swelling.