In this article, the development of a collaborative Internet-based simulation game for learning to solve knowledge management problems is described. The simulation game builds on two starting points: first, on psychological and pedagogical developments in learning and instruction, which are based on a shift from instructivistic toward constructivistic approaches; and second, on a perceived need for better training of people working in the emerging field of knowledge management. After having described these starting points in the introduction, the choice for using a simulation game is clarified and a set of assumptions that have been used to develop a simulation game are described. The resulting simulation game is described in the second part of this article together with the elements that have been implemented to support communication and collaboration at a distance, as well as those to support the learning process. The article ends with a summary of the results of the formative evaluation of the first prototype. The issue of collaboration via the Internet is a particular focus of discussion.