Thrombosis is a well-known clinical entity in systemic lupus erythematosus (SLE), and it is multifactorial. The most important risk factor is the presence of antiphospholipid antibodies (APLAs). However, approximately 40% of adults with SLE who are negative for APL A are diagnosed with thrombosis, indicating the importance of other risk factors. Thus, the thrombosis risk factors should be evaluated extensively and regularly and treated aggressively in every patient with systemic lupus erythematosus.