Research has established that ambidextrous organizations can successfully outperform their non-ambidextrous counterparts through exploitative and exploratory activities. However, there remains a scarcity of research on how managers orchestrate ambidexterity at the operational level, particularly in project delivery. Drawing on 55 qualitative interviews with middle managers on two engineering projects, we examine how managerial ambidexterity is enacted at the project level. We find that middle managers enable their own exploitative, exploratory and ambidextrous behaviors by invoking a repertoire of values selected from their organization’s cultural toolkit, which serve as cultural resources for action. We discuss how the cultural toolkit perspective can inform the relationship between managerial actions in day-to-day operations and organizational ambidexterity. Implications for theory and practice are presented.