In this paper, we explore the importance of silence in planning, an endeavor we deem relevant in an era where communication and planning are seen as nearly equivalent. We investigate the meanings and functions of silence in the interpretation of plans, planned space and the planning process. We distinguish silence in the literal sense, as absence of sound, and metaphorical silence, representing other forms of absence: of other voices, of oppressed discourse, of intentionality. The paradoxical nature of silence, as potential fullness and emptiness of meaning, increases complexity and unpredictability in the interpretation of space, plans and the planning process. It is argued that a process of participatory planning, including many actors, documents and interpretations of space, necessarily multiplies the ambiguities introduced by silence. This creates steering problems for planners, but it also introduces openness and flexibility. Silence can have the positive function of stretching up the interpretations of space, plans and the process.