Participatory research methods aim to break down the distinction between researchers and the researched. Infants are increasingly being seen as participants in research, but the nature of their participation is being questioned following an increased interest in participatory research with children. This article offers a perspective on participatory research that positions infant participants in ethically symmetrical ways to adult participants. It poses this can be achieved, when researchers adopt a methodological attitude that recognises, respects, and incorporates the active involvement of infants in research processes. Framed by the notion of ‘ethical symmetry’, the article draws on data from the author's doctoral work to demonstrate how attempts to achieve ethical symmetry were enacted. The importance of reciprocal and authentic relationships with infant participants as a driving force in the research is discussed, and implications for incorporating ethical symmetry in research with infants are discussed.