This chapter argues that the conception of autonomy implicit in the current health research ethics guidelines is an individualistic one. On this model, people are autonomous when they voluntarily exercise their deliberative capacities to make choices based on their values. They can fail to be autonomous either for psychological reasons, when their deliberative capacities are impaired; or for epistemic reasons, when they do not have access to all the information that is relevant to a decision. The chapter outlines a contrasting 'relational' approach to autonomy. On the relational model, people can fail to be autonomous for social reasons. The social conditions that a person inhabits, including their available options, and the interpersonal context – such as family relationships and social expectations – all affect the ability to make autonomous decisions. The chapter also identifies some of the implications of the relational model for health research ethics. It examines two issues implicit in the guidelines: the relationship between autonomy and vulnerability, and the claim that informed consent is sufficient for autonomy.