While the development of a blood biomarker as a screening or diagnostic tool for autism spectrum disorders is of great interest to the scientific and medical communities, it is also attracting intense scrutiny from other stakeholders including people with autism, ethicists, and parents. This symposium will therefore address the scientific, ethical and social challenges associated with the development of biomarkers for autism, and provide an update on the current status of research in this field. We will describe how the heterogeneity of autism, gender bias, and potential comorbidities, could derail the promise of identifying objective, reliable, and universally accepted biomarkers. We will consider the ethical and social issues relating to the development of biomarkers for autism in order to identify and describe the implications for the 'difference versus disability' debate; as well as consider possible wider tensions of biomarker research in relation to issues such as pre-natal screening and reproductive choice, and identity and inclusion for individuals on the autistic spectrum. Finally, we will summarize the most promising research on blood biomarkers for autism, describing the required steps to take a putative biomarker from the ‘bench to the bedside’. This educational symposium brings together researchers from scientific, ethical and psychological disciplines to provide a unique perspective on the utility of biomarkers for ascertaining autism risk, aiding in diagnosis and identifying therapeutic targets, all within the framework of the relevant ethical and social considerations.