As many as 40 patients with unstable angina (UA) were examined having been admitted into the clinic during the first twelve hours from the onset of ischemic manifestations. Depending on the type of therapy instituted, the patients were divided into two groups. Group I patients (n = 24) received acetylsalicylic acid (ASA), 160-325 mg daily, and a standard heparin in prescribed doses, group II patients (n = 16) was placed on a combination of ASA plus low-molecular heparin (LMH), nadroparin calcii, 0.1 mg/kg daily. It has been found out that anticoagulant treatment with different forms of heparin with a positive dynamics of general coagulating activity of the blood results in distinct changes in the system of fibrinolysis. Administration of a standard heparin is accompanied by exhaustion of the antithrombin activity of the blood and depression of fibrinolysis, which event comes to be especially dangerous in the arterial vessels. LMH (nadroparin calcii) therapy allows the negative sequelae to be prevented, and, quite the reverse, effects an intensification of fibrinolysis in the artery, this being particularly manifest at day 10 of the illness. A conclusion suggests itself that LMH has a beneficial effect on the system of hemostasis in general and on its fibrinolytic link in particular. Taking into account that the mechanism of action of LMH is toward the arterial blood, the above group of anticoagulants can be regarded as drugs of choice in those settings involving development of UA.