The use of genetics in medical research is one of the most important avenues currently being explored to enhance human health. For some, the idea that we can intervene in the mechanisms of human existence at such a fundamental level can be at minimum worrying and at most repugnant. In particular, religious doctrines are likely to collide with the rapidly advancing capability for science to make such interventions. The key ingredient for acceptance of genetics, on the other hand, is prototypically assumed to be scientific literacy – familiarity and understanding of the critical facts and methods of science. However, this binary opposition between science and religion runs counter to what is often found in practice. In this paper, we examine the association between religiosity, science knowledge and attitudes to medical genetics amongst the British public. In particular, we test the hypothesis that religion acts as a ‘perceptual filter’ through which citizens acquire and use scientific knowledge in the formation of attitudes towards medical genetics in various ways.