This paper is part of a broader discussion on the need for more in-depth study of workers' health surveillance practices, which are most often developed empirically, without well-defined theoretical or technical foundations. The paper presents a concept of surveillance in workers' health as a fulcrum for actions in the relationship between the work process and health. It emphasizes the exposure-based perspective involved in the epidemiological approach. Risk situations and effects are placed in spatial and technological context. The model provides an interdisciplinary approach with a technological, social, and epidemiological basis in a three-dimensional structure. A matrix for planning actions in workers' health surveillance is also presented, focusing on the connections between effects, risks, territory, and activities.