While project management has developed since the 1940s, it still does not take account of knowledge creation theory. Our research aims to demonstrate that knowledge is generated during project implementation. We adopt a practice-based approach and conduct action-research. The hospital information system case shows that knowledge is created through interaction micro-processes (knowing). These processes involve tacit knowledge, as defined by Polanyi, Duguid and Tsoukas. The project is then affected by tensions and controversies, according to Engeström, and these have implications for project management.