Antiphospholipid syndrome is an autoimmune disorder defined as association of vascular thrombosis and/or pregnancy complications with presence of antiphospholipid antibodies (lupus anticoagulant, anticardiolipin and anti-β2 glycoprotein I). It is the most common cause of acquired thrombophilia, and can occur as an independent entity or in relation with other diseases, especially systemic lupus erythematosus. Presence of antiphospholipid syndrome in systemic lupus erythematosus is additional vaso occlusive factor in already present inflammation, bringing further risk for thrombotic events. Clinical and serological manifestations of antiphospholipid syndrome and systemic lupus erythematosus are very similar, so possible connection for these two autoimmune disorders is assumed.