This paper highlights the effects of heterogeneous institutional contexts on transnational professional service firms, a relatively understudied issue. Specifically the paper provides empirical analysis of how the specificities of the Italian institutional context affect the activities of English legal professional service firms in Milan. This reveals the intimate connection between varieties of capitalisms, place-specific workplace cultures and practices, and the institution-related challenges transnational professional service firms and all transnational corporations (TNCs) face. The paper also reveals the way institutionally generated differences at the level of work practices are managed in transnational law firms through worldwide training programmes designed to ‘govern’ the practices of workers in different parts of the TNC’s network. This highlights the importance of studying attempts to manage institutional heterogeneity at the level of workplace practices, something often missed in existing meso-scale studies of TNCs’ governance structures. Consequently, detailed empirical archaeologies exploring the direct links between institutions and practices are highlighted as being an important as part of future research analysing the effects of institutions on TNCs.