Process knowledge is a vital prerequisite for employees to execute organizational processes successfully in the course of their daily work. However, the lack of process knowledge, especially concerning novice users, and the need for support pose a challenge to employers. Inspired by research on spatial knowledge and navigation, we conceptualize three process knowledge types addressing the needs of employees during their process execution. On the basis of these process knowledge types, we derive three theoretically grounded design principles for process guidance systems to support employees’ process execution. We instantiate the design principles and evaluate the resulting artifacts in a laboratory experiment and in a subsequent field study. The results demonstrate the positive effects of process guidance systems on users’ process knowledge and process execution performance. Our study contributes to research and practice by proposing a new conceptualization of process knowledge and a nascent design theory for process guidance systems that builds on theories of spatial knowledge and navigation, as well as decision support research.