Research questions In a study of teachers' learning in a VET college substantial problems of transfer were found (Jørgensen a.o. 2006). The paper explores, why transfer is so difficult to accomplish. It questions the conceptualisation of transfer as a process separate from learning, and discusses how transfer can be conceptualised to include the complex processes involved. This includes an assess-ment of some of the more recent contributions to the concept of transfer, building on pragmatist, socio-cultural and biographical theories. Methods The data consist of interviews with 20 teachers involved and observations of teaching. The transcribed interviews were analysed by three researchers in order to develop a more qualified understanding of the complex processes often involved in transfer. Results It is argued that transfer involves not only adjustments of mental and manual tools to a new situation, but a transformation of the skills and knowledge being used. Transfer may also involve transformations of the context for learning, of the social relations and the identity of the learner. In addition, transfer often takes place in connection with a transition of the learner between contexts and a transition in the life course of the learner and thus has a biographical dimension.