<p style="text-align: justify;">Premiers Cris is a research initiative that aims to rethink research practices in the field of early childhood, through a methodology combining Science &amp; Design. Premiers Cris facilitates the implementation of collaborative action-research projects in places welcoming children aged 0 to 6. In this article, we present the collaborative action-research methodology developed by Premiers Cris and illustrate it through a case study. We also share initial thoughts on the key elements of our methodology that we believe could promote the success of collaborative action-research intervention programs in childcare contexts. We hope that the questions raised by this new methodology will highlight the value of promoting research approaches that combine science, design and civil society to reduce developmental inequalities in early childhood.</p>