Background A vital component of research is patient and public involvement (PPI). The challenges of PPI increase when conducting cross-cultural research into sensitive subjects with marginalised ethnic minority groups.

Aim To present the authors’ reflections on conducting peer interviews with members of Roma, Gypsy and Traveller communities.

Discussion The authors provide examples of reflections on collecting data from a participatory research project that explored Gypsies, Roma and Travellers’ experiences of cancer in their communities. They derived the reflections from audio-recorded, post-interview debriefs with co-researchers from the same ethnic backgrounds as interviewees (‘peer researchers’). The main challenges for the peer researchers were cultural, linguistic and pragmatic, all fundamentally related to exploring a sensitive health topic through the lens of ethnicity.

Conclusion Peer researchers recognised their role in building bridges between participants and the research team. They did this by establishing a relationship of trust, minimising distress, representing the views of their communities and obtaining data to meet the aims of the project. Peer researchers perform multiple roles to assist in cross-cultural data collection in participatory research.

Implications for practice This article highlights underexplored aspects of peer researchers’ work that have implications for the planning and conduct of cross-cultural research with marginalised groups.