The BIAS FREE Framework is an integrative tool that can be used to identify and remove biases in health research that derive from any social hierarchy. This makes the BIAS FREE Framework an essential tool for getting at the roots of health-related social inequalities and producing clear and objective research reports, articles and funding proposals for decision-makers. While the BIAS FREE Framework is applicable not just to research but also to legislation, policies, programmes and practices, this publication focuses on its application to health research in particular. The Framework's strength lies in its ability to adapt its lens to hierarchy-rooted biases of all types, including gender, race, ability, class, age, geographical location and sexuality.