The contributionaims at reflecting on the need to focus on people in (research on) regional planning and development. We see participatory planning process as state of the art on different levels of spatial planning and development since decades now.Most of national and European programs donot only require participationin (regional) planningand development but regard it as a commonprinciple of democratic societies. Looking deeper into practice however, the situation is not as brilliantas it appears to be. Participation is often used synonymously to integrating people at a certain step of a planning process (e.g. local people in general or groups of people affected by a planning project). The way people are integrated is often determined and designed by experts. But participation in terms of equal association, cooperation, joint contribution and control points to a quality of relation between people that can not be simply „calculated”, „planned” or „executed”. The objectivation of people –„parametrisised” as „stakeholders” or „actors” –often turns out to be a (much hidden) epistemological problem of research and planning process. Transdisciplinaryresearch seeks to overcome the dichotomies (disparities, divides)byturning them into complementaritiesrealizing the need of co-operation between different qualitiesof knowledge. Following Gibbons et al. (1996) and Nowotny (1999) in their definition of transdisciplinarity as „mode 2” of research process, the presentation will discuss the consequences of focussing on people in research on spatial planning and development. It will point out the opportunities of transdisciplinarity in uncovering hidden potentials.