Peripheral arterial disease (PAD) is a major public health burden with a prevalence of approximately 27 million people in Europe and North America. PAD is characterised by a progressive narrowing or occlusion of the major arteries in the lower limbs as a result of atherosclerosis. Because atherosclerosis is a systemic disease, patients with PAD are at high risk of lower limb complications and of cardiovascular and cerebrovascular ischaemic events. Despite the growing awareness that PAD is an important marker of generalized atherosclerosis, its systemic consequences are still underestimated and undertreated in comparison with coronary artery disease or cerebrovascular disease. To raise awareness and improve secondary prevention, this thesis focussed on the long-term prognosis of patients with PAD who were treated with infrainguinal bypass surgery. Our primary aim was to quantify the risk of ischaemic complications throughout the whole arterial tree up to 10 years after bypass surgery and elucidate its determinants. Data on fatal and non-fatal vascular events that occurred between 1995 and 2009 were recorded in nearly 500 patients who had participated in the Dutch Bypass and Oral anticoagulants or Aspirin (BOA) Study (The Lancet 2000;355:346-351). The follow-up data were complete in 94% of patients and enabled us to give a fairly accurate insight in the long-term course of PAD and to produce an easy to use tool to determine a patient’s vascular risk profile. This so called BOA Risk Chart helps to predict a patient’s long-term prognosis quickly and effortlessly without the need for any additional testing. Furthermore, we studied the former and currently applied drug treatments (i.e. antithrombotic, antihypertensive, and lipid lowering drugs) and cardiovascular risk management in PAD patients after they underwent peripheral bypass surgery. Both the results of our international survey among vascular surgeons throughout Europe and of our drug registration over the past decade in a sample of patients from the Dutch BOA ...