Book of proceedings: Annual AESOP Congress, Definite Space – Fuzzy Responsibility, Prague, 13-16th July, 2015 ; Spatial planning practices are constantly evolving to be more effective in a dynamic context. In the face of the latest developments, the practice of collaborative spatial planning through the formation of regional collaborations has emerged as the contemporary solution. The practice of working with a multitude of public actors that cooperate to formulate spatial strategies for issues that transcend their own planning capacity is relatively new and the ideal structure, organization and scope are yet unclear. The ability to of a region to successfully develop joint strategies is referred to as a region’s strategic capacity. As a means for comprehensive assessment of the effectiveness of such collaboration projects an evaluation framework is proposed to assess a region’s strategic capacity. To this end, the paper further elaborates the concept of strategic capacity. And furthermore it develops an evaluation framework specifically designed for the evaluation of regional collaborations and the strategic capacity generated. It is shown that this framework has a high potential for meaningful evaluation of regional planning collaboration projects. ; Published Version