Modern commercial organisations are facing pressures which have caused them to lose personnel. When they lose people, they also lose their knowledge. Organisations also have to cope with the internationalisation of business forcing collaboration and knowledge sharing across time and distance. Knowledge Management (KM) claims to tackle these issues. This paper looks at an area where KM does not offer sufficient support, that is, the sharing of knowledge that is not easy to articulate. The focus in this paper is on Communities of Practice in commercial organisations. We do this by exploring knowledge sharing in Lave and Wenger's  theory of Communities of Practice and investigating how Communities of Practice may translate to a distributed international environment. The paper reports on two case studies that explore the functioning of Communities of Practice across international boundaries.