This study presents the results of a research project whose objective is to propose measures to evaluate the right of children to engage in play, as recognised in the Convention on the Rights of the Child. After exhausting documentation and statistical sources, a lack of measures related to this right was clear. This led to the formation of discussion groups about play with schools, families and social agents. From this, an initial matrix was developed and submitted to experts who selected the most suitable measures. This resulted in the SIDERJU matrix, composed of measures for the structure, process and result. © 2018 John Wiley & Sons Ltd and National Children’s Bureau