Scientists, health care professionals and the general public have all raised concerns about the potential health impact natural and manmade sources bioaerosols. In response in september 2012 the Natural Environmental Research Council and public health England jointly funded a workshop to review the 'sources, quantification and health implications of bioaerosols'. The organising committee for the workshop identified five priority areas-(1) bioaerosol identification and quantification methodology, (2) bioaerosol sources, (3) health effects of bioaerosols, (4) extreme events, risk assessment and mediation and (5) bioaerosol dispersion and modelling. The primary purpose was to bring together experts to report on recent research and identify research gaps where increased knowledge would improve risk understanding and public health. This report summarises the presentations, the main discussion points and key conclusions that emerged during the workshop.