Do psychosocial factors cause coronary heart disease or affect survival among patients with coronary heart disease? Here we use an explicit methodological quality filter to review systematically the prospective cohort studies testing specific psychosocial hypotheses. This review of the epidemiological literature identifies the psychosocial factors that have been most rigorously tested. Only four psychosocial factors met the quality filter: type A/hostility, depression and anxiety, work characteristics, and social supports. The importance of other study designs—for example, ecological1 or nested case-control2^–4 studies—is acknowledged. The review should be seen as complementary to existing reviews5^–8 on single psychosocial factors and as a challenge to investigators in the field to ensure that the systematic review is made unbiased, kept up to date, and used to guide future hypothesis testing.