Abstract In the 50 years after publication of Bradford Hill?s ?criteria? for inferring causality, an enormous amount of data has accumulated in epidemiology, and refined methods for examining evidence have been developed. Considering the importance of the ?criteria? in public health decision making, it is timely to re-assess their utility for distinguishing association from causality. As a group of scientists from Brunel University London, London School of Hygiene and Tropical Medicine and the Royal Society of Medicine we are organizing a workshop with high profile international speakers to re-assess Bradford Hill?s legacy in the light of today?s knowledge about multi-causality. The ambition is to evaluate and, if needed, update the Bradford Hill paper. The event will be held on 13- 14 Oct 2016 at the very venue of his famous lecture, the Royal Society of Medicine in London. Kenneth Rothman, Kurt Straif, Paolo Vineis, Sir Richard Peto, Dame Valerie Beral and others will participate. We are seeking 8,000 to cover the travel costs of speakers, so that the attendance fee for workshop participants can be kept affordable. To maximize the impact of the workshop we aim to disseminate workshop outcomes in a high impact journal.