1 A final version of this article was pubished in BioSocieties, 4(4): 335-348, doi: http://dx.doi.org/10.1017/S1745855209990329 Informed consent in forensic DNA databases: volunteering, constructions of risk and identity categorization Helena Machado and Susana Silva, 2009 Helena Machado (corresponding author) Research Center for the Social Sciences, University of Minho, Portugal; Center for Social Sciences, University of Coimbra, Portugal. E-mail: hmachado@ics.uminho.pt Susana Silva Department of Hygiene and Epidemiology, University of Porto Medical School, Portugal; Research Center for the Social Sciences, University of Minho, Portugal. E- mail: susilva@med.up.pt Acknowledgments We would like to thank the Foundation for Science and Technology (Portuguese Ministry of Science, Technology and Higher Education) for financing this research through a post-doc fellowship SFRH/BPD/34143/2006 (2007-2010) and the project “Forensic DNA databasing in Portugal: Contemporary issues in ethics, practices and policy” (PTDC/CS-ECS/098148/2008). Abstract In this paper we aim to expand the traditional ethical issues related to the use and storage of genetic information in forensic DNA databases by exploring the Portuguese practices of informed consent in the context of DNA sample collection for forensic processing. This paper focuses on three interrelated domains: the practice of volunteering to contribute to the Portuguese forensic DNA database; the portfolio of risks presented to prospective DNA donors through the use of information sheets and informed consent forms; and the ethical implications of requesting donors’ ethnic group among their personal data. We argue that the Portuguese forensic DNA database is an interesting case study to re-focus the ethical debate on the implications of collecting