We consider the successful early emergence of cooperative creameries in Denmark in the late nineteenth century within the framework of the ‘new institutional economics’ presented by Williamson (2000). Previous work has focused on the social cohesion of the Danes, but we demonstrate that this was not sufficient for the success. The Danish legal system, which we compare to that of other countries, was also of crucial importance, along with the way in which rules were monitored and enforced. Of particular importance was the Danish cooperatives’ use of contracts, which we explore with evidence from a variety of primary and secondary sources.