PurposeThe purpose of this paper is to explore the emotional dynamics of the corporate acceleration process, using the systems psychodynamics perspective.Design/methodology/approachThe study applies inductive multiple case study of embedded 10 cases of corporate acceleration, covering both incumbent and startup perspectives, occurring in the context of a corporate accelerator.FindingsWe find that (1) the process of corporate acceleration involves three phases, each of them is dominated by a different emotional state (hope, anxiety and acceptance), triggering different behavioral responses; (2) as a means to deal with negative emotions, entrepreneurs and corporate acceleration program's team members develop different mechanisms of dealing with contradictories in subsequent acceleration phases (defense and copying mechanisms), which are reflected in their behaviors. Coping mechanisms with goal reformulation (i.e. refocus from the officially declared “open innovation” goals toward mainly symbolic ones) is an effective strategy to manage negative emotions in third phase of the acceleration.Research limitations/implicationsOur sample is limited to two relatively similar accelerators established by telecom companies, and therefore, our theoretical and practical conclusions cannot be generalized.Practical implicationsWe supplement the studies of corporate accelerators that imply how to design them better and improve decision-making rules with recommendation that in order to improve their effectiveness in terms of learning and innovations, their managers need not only to learn how to manage structural and procedural differences but also how to overcome social defenses triggered by corporate–startups cooperation.Originality/valueBy documenting a multidimensional impact of acceleration process, and especially shedding light on psychodynamic aspects behind such liaisons, this paper contributes to richer understanding of corporate–startup relationships, typically examined through a rationalistic lens of strategy literature. The study contributes to interorganizational research and open innovation literature, by showing that corporate acceleration process is marked by phases based on the type of emotions intertwined with the nature and dynamism of its life cycle. It indicates how these emotions are managed depending on their type.