Hydroxychloroquine is used extensively in the treatment of systemic lupus erythematosus, not only for its benefit for cutaneous and musculoskeletal lupus, but also for its role in preventing flares, preventing renal and central nervous system lupus, and improving survival rates. Hydroxychloroquine also has known benefits in reducing some traditional cardiovascular risk factors, such as hyperlipidemia and diabetes mellitus. This article reviews its possible role as an antithrombotic drug in the general population, in systemic lupus erythematosus, and in patients with antiphospholipid antibodies.