The article discusses research oriented towards spatial planning evaluation practices as an important contribution to achieve positive improvements on the efficiency and effectiveness of the planning system. A significant part of current planning problems are directly connected with the necessity of dealing with uncertain scenarios and future dynamics variations. This increasing uncertainty has been engaging the plan making process and is currently leading urban planners to flexible planning models especially supported on monitoring and evaluation mechanisms. The research focuses on the evaluation theories and the methodologies that have been developed around the world, seeking to present a survey on the state of the art on the matter. A focus is therefore established on three evaluation methodologies (General Plan Evaluation Criteria; After the Plans; and the Policy – Plan / Programme – Implementation – Process) and some measures are identified in order to adapt and apply these theories to the main instrument of Portuguese local planning system – the PDM (Plano Director Municipal). The findings show the benefits of the evaluation practices in spatial planning, as well as the advantages for the sustainability of the Portuguese local planning system. Moreover, the research identifies positive contributions coming from these specific methodologies to the evaluation of the Portuguese local master plans (PDM).
