The paper describes our usage of and experience with the method of participatory systems mapping. The method, developed for the purpose of facilitating knowledge brokerage, builds on participatory modelling approaches and applications and was used in several events involving both researchers and policy makers. The paper presents and discusses examples of how different types of participatory interaction with causal loop diagrams (‘system maps’) produced different insights on issues related to sustainable consumption and enabled participatory reflec- tion and sharing of knowledge. Together, these insights support a systemic understanding of the issues and thus the method provides instruments for coping with complexity when formulating policies for sustainable con- sumption. Furthermore the paper discusses the ability of the method — and its limits — to connect mental models of participants through structured discussion and thus bridge boundaries between different communities.