The Fourth Annual NIHR Imperial Patient Safety Translational Research Centre (PSTRC)/Centre for Patient Safety and Service Quality (CPSSQ) Symposium was held on 28^th September 2016 at the Royal School of Mines, South Kensington Campus, Imperial College London. It continued the long-standing tradition of engaging researchers, healthcare professionals and members of the public in the latest patient safety research from NIHR Imperial PSTRC, CPSSQ and other organisations.