Organizations can increase and change their knowledge base both through the learning of their members and through the acquisition of new members and the knowledge that they possess. This last, which Huber (1991, Organization Science, 2(1), 88-115) terms learning through grafting, is a very important vehicle for learning in Western firms. This article presents a model of learning in ventures in new areas, where grafting has been an important means. It is based on interviews with senior management involved in 13 major ventures intended to renew and reorientate mature firms, and on their view of the learning process. The article shows how the companies concerned acted to acquire new knowledge and to develop new competence, and the factors affecting their learning process. At the same time it represents one way of thinking about learning through grafting in new ventures.