Thirty patients with systemic lupus erythematosus (SLE) and suspected secondary antiphospholipid antibody syndrome (APLAS) were evaluated in the study based on their clinical manifestations. The aim was to study the prevalence of various antiphospholipid antibodies, compare the tests used for their detection and to find a correlation between clinical and laboratory parameters. Coagulation tests used were activated partial thromboplastin time, dilute Russell viper venom time and kaolin clotting time and the results were analyzed statistically. In our study, arteriovenous thrombosis was more common than recurrent abortions and other clinical manifestations. Twelve percent of patients had positive lupus anticoagulant and 78% had elevated anticardiolipin antibody titers. We concluded that the prevalence of lupus anticoagulant and anticardiolipin antibodies in SLE patients with secondary APLAS was 12% and 17%, respectively. We also proved that dilute Russell viper venom time and kaolin clotting time proved to be much more specific tests and the anticardiolipin antibody a much more sensitive test.