Responsibility for flood risk management (FRM) is increasingly being devolved to a wider set of stakeholders, and effective participation by multiple FRM agencies and communities at risk calls for engagement approaches that supplement and make the best possible use of hydrologic and hydraulic flood modelling. Stakeholder engagement must strike a considered balance between participation ideals and the pragmatic realities of existing mechanisms for FRM decision-making. This article evaluates the potential for using participatory modelling to facilitate engagement and co-production of knowledge by FRM modellers, practitioners and other stakeholders. Participatory modelling offers an approach that is flexible and versatile, yet sufficiently structured that it can support meaningful representation of scientific, empirical and local knowledges in producing outcomes that can readily be integrated into existing procedures for shared decision-making. This article frames the qualities of participatory modelling useful to FRM, as being accessible, transparent, adaptable, evaluative and holistic. These qualities are used as criteria with which to assess the practical utility of three popular participatory techniques: Bayesian networks, system dynamics and fuzzy cognitive mapping. Case studies are used to illustrate how each technique might benefit FRM options appraisal and decision-making. While each technique has potential, none is ideal, and local contexts will guide selection of which technique is best suited to deliver effective stakeholder participation.