To evaluate the analgesic and antiinflammatory properties of oral streptokinase-streptodornase (SS) in cases of minor trauma, 190 patients with ankle sprains were studied. Subjects were randomly given an active drug or a placebo in doses of two tablets three times a day for eight days. A scoring system was used to rate the following symptoms: spontaneous pain, mobilization pain, wearing pain, articular disability, flaccidity, muscular spasm, edema, and hematoma. Each symptom was categorized as none (0), mild (1), moderate (3), or severe (4). Patients were evaluated at the beginning of the study and on the fourth and eighth days of treatment. At the end of the trial, the decrease in each symptom score was significantly greater in patients receiving SS than in patients receiving a placebo. Analgesic intake during the study was also noticeably lower in the SS group. The incidence of drug-induced side effects (mainly abdominal discomfort) was minimal. Oral SS ameliorates the inflammatory symptoms associated with ankle sprains and therefore may be used as an alternative to nonsteroidal antiinflammatory drugs.