A total of 212 patients with acute sports injuries were allotted at random to treatment with 20 mg tenoxicam daily, 20 piroxicam daily or a placebo for ten days. The injuries could be subdivided into six groups: Tendinitis, periostitis, sprains, tendovaginitis, epicondylitis and muscular ruptures. Treatment was well tolerated and analysis of the total material showed a slight but significantly better effect in the group treated with the active drugs. More detailed analysis revealed that this increased effect was produced by a definitely better therapeutic result in the group of patients with tendinitis treated with non-steroid anti-inflammatory drugs (NSAID) while, in the other types of injury, no definite effect could be observed. On the basis of these observations, the authors conclude that acute tendinitis may be treated with NSAID (tenoxicam) while the question is not yet solved where other acute stress-induced injuries are concerned.