Normal haemostasis depends on a balance between coagulation and fibrinolytic processes. Because of this concept of balance between coagulation and fibrinolysis, drugs which retard or inhibit the breakdown of fibrin encourage haemostasis. Such drugs are used in patients undergoing dental extractions and as prophylactic agents to prevent spontaneous bleeding. Blood clotting factors produced by genetic engineering are now becoming available and these offer exciting prospects for the management of patients with bleeding disorders.