The globalisation of firms is explored at theoretical and empirical levels. The idea is that a global firm is a multi-cultural team. The existence of a global firm is somewhat puzzling. Combining workers who have different cultures, legal systems, and languages imposes costs on the firm that would not be present were all workers to conform to one standard. In order to offset the costs of cross-cultural dealing, there must be complementarities between the workers that are sufficiently important to overcome the costs. The search for the ‘best practice’ is analysed and empirical support from an examination of trading patterns is provided.