Due to its fibrinolytic activity, alpha-chymotrypsin should be applied, even in doses of 5 and 10 mg (as indicated in the List of Drugs) only for postoperative oedema and haematoma prophylaxis, with due regard to the simultaneous effect on haemostasis. The maximum of fibrinolytic activity was observed 6 to 9 hours after intramuscular injection. These findings are consistent with clinical observation. The authors dissuade from uncontrolled use because, in spite of many separate experimental studies and clinical trials, there are still numerous questions that must be considered unsettled.