The capacity for planning and performing physical actions enables people and animals to gather information, manipulate objects, express decisions, and communicate with others. Physical actions are not only important for enabling cognition, however. They also manifest what we know, often in subtle ways or in ways that reflect knowledge of domains that have not been traditionally susceptible to analysis by cognitive psychologists (e.g., biomechanics). This chapter reviews cognitive psychological research on planning and performing physical actions, first by focusing on the knowledge revealed through such actions (via practice effects and anticipation effects), and second by focusing on the realization of action, both in verbal and nonverbal domains. The last sections describe a cognitive psychological model of action production and offer reflections on the place of this somewhat neglected area of study in cognitive psychology.