Richard Peto is an epidemiologist, working in Oxford University’s Nuffield Department of Population Health. He has helped show that over half of all persistent smokers are eventually killed by tobacco, but that smokers who stop before age 40 avoid >90% of the risk. He has also shown that if current smoking patterns persist then tobacco will cause about 1000 million deaths in the present century, as against “only” 100 million in the twentieth century. He has helped establish large studies of smoking, drinking, adiposity, diabetes and blood pressure in many different populations in Europe, the Americas, China, India, Russia and South Africa, demonstrating large international differences in the importance of these major avoidable causes of vascular morbidity and mortality. The Oxford group have undertaken large collaborative randomized trials and meta-analyses of trials in vascular disease, showing that several widely practicable treatments can substantially improve long-term survival.