Antiphospholipid antibodies (APLA) present very heterogeneous groups of antibodies which can significantly and in various ways influence processes on different levels of coagulation cascade. Their presence can be accompanied with repetitive venous and arterial thromboses, recurrent loses of foetus, and thrombocytopenia. Incidence of these thrombotic disorders was monitored in a group of 46 patients with systemic lupus erythematodes (SLE). Positive lupus anticoagulant (LA), antiphospholipid antibodies complex, and thrombocyte counts were assessed. Thrombotic disorders were assessed in a retrospective analysis. In the LA+ group 62% of patients had history of venous thromboses, 31% had history of arterial thromboses, and 18% had history of spontaneous abortions. In a group without positive LA 18% of venous thromboses (p = 0.0006) and 6% of arterial thromboses (p = 0.03) were indicated. In the assessment of spontaneous abortions no statistically significant difference was found. An average value of thrombocytes in LA+ group was 152 +/- 66 x 10(5)/l, in LA- group 223 +/- 86 x 10(5)/l, which is statistically significant difference (p < 0.05). In the assessment of thrombotic disorders in a group with combination LA+ and APA+ statistical significance was indicated only in venous thromboses (p = 0.004). We can state from the results that in thrombotic disorders which can be seen in the framework of systemic tissue disorders positive LA and APA and a range of other factors such as activity of a basic disease, associated diseases, and treatment which can aggravate thrombotic disorders of individual patients can participate.