Participatory Planning (PP), as a streamline approach in coping with sustainability concerns, is nowadays largely acknowledged in research and policy makers' community as a ‘bridge' between decision-making processes and society. Its implementation implies substantial preparation, ending up with certain choices on participation tools, relevant for use at the different stages of the planning process. However, lack of planners' deep insight into such tools leads them to either follow well established traditional planning paths, discouraged by a possible failure of participatory attempts; or join PP processes that lead to unsuccessful planning outcomes and frustrating participation results. The contribution of this article lies on increasing capacity of planners towards more informed PP tools' selection by: providing an exhaustive list/explanation of factors affecting such choices in each single PP context; and sketching the architecture/functioning of an e-Decision Support System (e-DSS) as a tool supporting planners towards the design of more effective PP processes.