Purpose – This article aims to examine how the agile approach interrelates with project complexity in product development. Design/methodology/approach – The study adopts a case study approach, using multiple dimensions of project complexity as an analytical framework to examine two complementary product development projects that involved the agile approach. Findings – The findings reveal that the interrelationship between the agile approach and project complexity is intricate and, at times, contradictory. While the agile approach helps manage certain dimensions of project complexity, other dimensions may hinder its effective application. The article also reveals how the dimensions of project complexity interact with one another, shaping their interrelationship with the application of the agile approach; these interactions warrant exploration in future research. Practical implications – This article raises the awareness of project management and ownership roles that the application of the agile approach can help manage project complexity, although its benefits may also be constrained by that same complexity. Considering the dimensions of project complexity helps prevent overlooking factors that could hinder the application of the agile approach and the realization of its benefits. Originality/value – This article advances the understanding of how the agile approach interrelates with project complexity, moving beyond technological complexity, which is commonly emphasized. It demonstrates that overlooking dimensions of project complexity such as interorganizational complexity undermines the application of the agile approach and its benefits