The relation between epidemiological research results and policy-ma king is reviewed. Apparently, traditional models of policy-making (incrementalism, mixed scanning synoptic planning) do not explain why research findings are hardly used in policy-making procedures. It is suggested that this phenomenon is related to three determinants of policy-making: (i) a bias stemming from sets of causal, final and normative assumptions and presuppositions; (ii) interest webs of groups in certain domains; and (iii) the power of organizations to monitor and communicate. The conclusion is that epidemiologists should engage in the policy-making process more consciously and conscientiously.