Bowel cancer is a serious health problem in developed countries. Australia, the United Kingdom (UK) and New Zealand (NZ) reviewed the same randomised controlled trial evidence on the benefits and harms of population-based bowel cancer screening. Yet only NZ, with the highest age standardised rate of bowel cancer mortality, decided against introducing a bowel cancer screening programme. This case study of policy making explores the unique resource, ethical, institutional and political environments in which the evidence was considered. It highlights the centrality of context in assessing the relative worth of evidence in policy making and raises questions about the suitability of knowledge utilisation strategies.