Thrombo-embolic disease is an increasingly recognised complication of several vasculitides. A common observation is that thrombo-embolic complications coincide with periods of increased vasculitis disease activity, but the mechanism through which this happens is still unknown. Thrombo-embolic disease has been recognised for decades as a significant contributor to the morbidity and mortality of Behçet's disease, and the role of anticoagulation in its management is being minimised in favour of immunosuppression, although evidence from randomised controlled trials is lacking. Ancillary data from a randomised clinical trial and retrospective observational studies have confirmed an association between venous thrombo-embolic disease and vasculitides associated with anti-neutrophil cytoplasmic antibodies (ANCAs). An increased cardiovascular risk is now also recognised for vasculitides associated with ANCAs. Thrombosis plays a prominent role in the pathogenesis of thromboangiitis obliterans (Buerger's disease). The association of thrombosis with other vasculitides such as giant-cell arteritis and levamisole-induced vasculopathy is under investigation. © 2012 Elsevier Ltd. All rights reserved.