Integrated planning processes involve an increasing number of actors and aim to create synergy between multiple knowledges in communicative settings. Planning research has acknowledged that the actor-relational aspects of planning processes are not yet adequately understood, and that methods to reveal the often- invisible dynamics and their possible effects over time require development. This research aims at developing a methodological contribution for revealing the socio-communicative complexities of integrated planning processes, by focusing on the aspects of knowledge co-creation and process memory development. Actor- relational dynamics are explored through social network analysis and qualitative methods, using longitudinal data from a four-year strategic spatial planning process in the Finnish context. The findings indicate that a range of actor-relational dynamics affect the level of sectoral and scalar integration over time, and that social complexities have an essential role in enabling knowledge co-creation and process memory development. Unveiling actor-relational dynamics is a promising research direction, requiring new methods for bridging research and practice, and re-centring the need for understanding planning practice on the actor-relational level.