ABSTRACT Green spaces provide multiple benefits to physical and mental health, especially for children. Meanwhile, children are not typically included in most participatory processes regarding green spaces and their needs, if at all, tend to be represented by adults. This study attempts to answer the following research questions: (1) Does the degree of children’s participation differ depending on the spatial scale of green space planning processes? (2) How can children’s participation be interpreted in the context of environmental justice? We used mixed methods to assess the legal condition, process flow and products of three participatory processes regarding green space planning in Lodz (Poland). Our findings demonstrate that even the seemingly well-intentioned processes may fail to adequately incorporate children because of procedural inconsistencies and other deficiencies. Even if a process allows children to express their opinions, it fails to translate these voices into reality. We highlight the need to increase awareness of the importance of children’s inclusion in participatory processes to guarantee that their needs are considered, endow children with pro-environmental behaviours, and promote the idea of civil society. We contribute to the environmental justice debate by demonstrating the necessity of differentiating between procedural and participatory environmental justice dimensions.