Preserving and fostering knowledge is the vital interest of a network-like virtual organization. The decentralized and geographically distributed organizational structure inhibits knowledge flow. The particular conditions of knowledge management in virtual organizations are discussed by the example of an empirical study we carried out in a service company. We analyze how technical and organizational aspects influence knowledge sharing and transfer. Particular emphasis is placed on supporting knowledge transfer. It is shown how an existing knowledge sharing tradition had to be extended and which drawback it had concerning technology use. To improve knowledge flow within the organization a web-based knowledge base was introduced. This initiated a process of externalizing tacit knowledge and is meant to introduce new ways of knowledge transfer to the organizational culture. In fluid virtual organizations sustained knowledge management means to establish an organizational memory that is f...