The aim of this paper is to present some of the challenges and limitations of evidence-based policymaking from an ethical standpoint using specific case-studies in which the author has been involved. The questions addressed in this presentation will be:

1. How to deal with uncertainty when evidence is lacking? The case of technologies for screening and treating prostate cancer will be presented.
2. How to deal with conflicting recommendations from professional societies? The case of recommendation for cholesterol screening will be presented.
3. How much evidence is enough for effective policy-making? The results of a cumulative meta-analysis comparing primary angioplasty with thrombolytics in the treatment of acute myocardial infarction will be presented.
4. How policy-makers will address conflicting evidence from randomized controlled trials? The results of a meta-analysis and subgroup analysis comparing thrombolytic therapy with placebo in the treatment of stroke yielding contradictory evidence and with a number of selected health outcomes will be presented.
5. How evidence-based policymaking will incorporate patient preferences? The results of a decision analysis comparing prenatal screening policies for Down syndrome will be presented.
6. How to make policy decisions when lack of evidence conflict with patients' wishes? A review of scientific evidence of treatment of breast cancer with bone marrow transplant with stem-cell and high-dose intensive chemotherapy will be presented.