Strategic spatial planning is increasingly practised throughout the world to develop a coordinated vision for guiding the medium- to long-term development of urban regions. However, from a theoretical and conceptual perspective, strategic spatial planning is hard to grasp, as it is multidimensional, embedded in sociopolitical and institutional complexity and highly context-dependent. Moreover, current planning debates mainly focus on the outputs of the strategic planning process while largely neglecting the impact that strategic spatial plans can have on urban transformations. Here, we show an empirically-based analytical framework grounded on an analysis of 21 European urban regions, representing the key components of plan-making and plan-implementation as well as the main interrelationships among them. The proposed framework (SPlaMI) reflects current planning practices and intends to contribute towards consolidating a European understanding of strategic spatial planning while providing the basis for dialogue with broader discourses on sustainable development in a global context.