This master thesis explores the nature of public participation as a central and most current subject in the field of urban planning. A first impression exposes a seemingly unanalyzed consensus on the values and benefits which public participation provides the process of urban planning. The city may be a concern to all its inhabitants; hence knowledge and opinions of the local public are of great importance for the urban development. But is there really something new to these assumptions, and are the advantages of increased public participation in urban planning always obvious?   By using action research as a main method, I have put myself into the context of the Swedish municipality of Nacka and their projects dealing with the development of public participation. The research process combines my support in practice and documentation with the investigation of established theories, the public discussion on public participation, as well as the rise of the matter. By doing so this thesis assigns to the task of portraying the current state of public participation in urban planning in a Swedish context.  The case studies, performed in Nacka, reveal what the measures of a municipality consist of and on what goals these initiatives are based, while at the same time investigating whether action researching the local case could generate more general conclusions and guidelines for public participation. The research swiftly leads to a number of reoccurring advocating arguments. These are given ground for by either strengthening or making the planning process more efficient, or by putting emphasis on the democratic aspects of ascribing power and influence to the citizens. Nevertheless there is critique and skepticism as well, highlighted in arguments of inefficiency and incompatibility with representative democracy. Theories on, for instance, multiple publics and Arnstein’s ladder of participation are close at hand, when analyzing the friction between the views and their relevance in practice. Nevertheless, the ongoing debate and discussion turns out to handle the potential conflicts in a general and unproblematized way. One discusses why public participation is important, but rarely how and when. That in itself says quite a bit about the current views on the matter. At that point this action research turns out to generate a valuable discussion and vital posers concerning e.g. clarity and aims when involving citizens, the significance of both phase and level of participation, the role of physical/technical preconditions for dialogue, and the measures required to turn temporary projects into continuous processes and established routines.  The thesis indeed focuses on a specific municipality. However, by connecting a practical case to both ongoing discussions and more or less well known theoretical concepts, it hopefully offers increased apprehension and widening perspectives to planners, regardless of their location.