The academic debate on governance in project management is dominated by research that looks at the structure of governance regimes, but there is very little research on the micro-practices of governance as it actually takes place. This paper fills this gap by focusing on the governance practices of project employees and looking at megaprojects as cultural phenomena. Therefore, a one-year ethnographic field study of the Panama Canal Expansion Megaproject was conducted to examine the cultural practices of governing. In the study, five cultural practices were found to influence the governance of this megaproject: (1) ritualizing the bid-winning ceremony, (2) changing teams, (3) struggling over governance structure, and labeling according to (4) national and (5) organizational cultures. This paper makes a contribution to the current debate by offering a cultural approach of megaprojects and by including a case that shows how ex post micro-processes of governing can start escalation in megaprojects.