BMJ Open is a peer-reviewed open access medical journal that is dedicated to publishing medical research from all disciplines and therapeutic areas. It is published by BMJ and considers all research study types, from protocols through phase I trials to meta-analyses, including small, specialist studies, and negative studies. Publishing procedures are built around fully open peer review and continuous publication, publishing research online as soon as the article is ready. BMJ Open aims to promote transparency in the publication process by publishing reviewer reports and previous versions of manuscripts as prepublication histories.The editor-in-chief is Adrian Aldcroft.