Encouraging a sound Health, Safety and Environmental (HSE) culture is a regulatory requirement for petroleum companies operating on the Norwegian Continental Shelf. Although regulators in different industries have increasingly included safety culture in their regulatory repertory, it is still rare that regulators explicitly require sound cultures. In this paper we study how the requirement is ‘translated’ in two different petroleum companies, discuss why the translations differ and the extent to which they represent good organizational learning about HSE. Translation is seen as a form of organizational learning. The analysis is based on institutional theory, and a virus metaphor for adoption of organizational ideas.