A substantial body of theoretical and practical knowledge has been developed on continuous improvement. However, there is still a considerable lack of empirically grounded contributions and theories on collaborative improvement, that is, continuous improvement in an inter-organizational setting. The CO-IMPROVE project investigated whether and how the concept of continuous improvement can be extended and transferred to such settings. The objective of this article is to evaluate the CO-IMPROVE research findings in view of existing theories on continuous innovation. The article investigates the similarities and differences between key components of continuous and collaborative improvement by assessing what is specific for continuous improvement, what for collaborative improvement, and where the two areas of application meet and overlap. The main conclusions are that there are many more similarities between continuous and collaborative improvement. The main differences relate to the role of hierarchy/market, trust, power and commitment to collaboration, all of which are related to differences between the settings in which continuous and collaborative improvement unfold.