To develop an approach that captures the intricacies of transition dynamics in the Cities of the East, this chapter explores existing entry points for understanding the place-specificity of transition processes. Building on existing insights within transition studies and relational approaches to space, it introduces the notion of spatial complexity to understand multilevel transition processes. This conceptual discussion is followed by an account of the spatial complexity of unfolding transition processes in the Cities of the East. The chapter discusses the scalar legacies of the Soviet-era urban planning regime, which strongly shapes the nature and origins of sustainability challenges in the Cities of the East. It then explores emerging responses to the significant urban unsustainabilities affecting post-socialist cities. By exploring various spatialities – urban territories, scales and networks – involved in the transition process at hand, the chapter posits that transition studies have much to benefit from understanding transitions as emerging and unfolding phenomena at the intersection of multiple spatial forms.