The antithrombotic therapy of the antiphospholipid syndrome (APS) has long been based on an empirical strategy. In the absence of appropriate randomised controlled trials, data of retrospective cohort studies were used to establish these strategies. Here we report the results of recent clinical trials, what they add to patient management and the issues that remain unsolved. SECONDARY PROPHYLAXIS OF THROMBOTIC EVENTS: While there is a consensus for prolonged vitamin K antagonist anticoagulation after a first event, two recent randomised clinical trials have compared various intensities of anticoagulation. Both studies have shown that high intensities of warfarin were not superior to conventional intensities. Patients included in these studies had mainly venous thromboembolic events. There has been no study comparing different antithrombotic strategies for arterial thrombosis associated with APS. The WARSS/APASS study, in particular has not been conducted in patients with definite APS and should not be applied to these patients. For now, vitamin K antagonist anticoagulants should remain the treatment of choice in these patients. PRIMARY PROPHYLAXIS OF THROMBOTIC EVENTS: Because of the high incidence of thrombotic events in asymptomatic patients with antiphospholipid antibodies, especially in systemic lupus erythematosus, a clinical trial compared aspirin and placebo in this setting. This study did not demonstrate any benefit of aspirin. We conclude that recent clinical trials indicate the optimal antithrombotic strategy in APS with venous thromboembolism. However, the best options for patients with arterial thrombosis and for primary prophylaxis remain to be established by further studies.