Drawing on a critical debate in the social studies of childhood on the empowerment of children to participate in research, the paper illustrates how ethnographic research in childhood institutions has the potential to destabilise hierarchic power relationships towards an open, dynamic, playful engagement between ethnographer, children, and the material of the classroom. Ultimately, we suggest that conceptualizations from new posthumanist materialism open up new ways of theorising participation in ethnographic research in childhood institutions and fine-tune its capacity for reflecting processes of knowledge production with children.