The effects of lean manufacturing on worker health remain poorly understood. Although recent studies show a moderating role of human resource management (HRM) practices on this relationship, they focus only on some specific HRM practices and do not grasp their effects on the different phases of the lean adoption process. By considering lean manufacturing as a managerial innovation, the objective of this paper is to explore the relationship between lean, HRM practices, and worker health according to the firm’s lean maturity (i.e. intensity of usage and stage of adoption). The results, based on three case studies of French industrial firms, show that the effects of lean practices on worker health should be assessed in light of the combination of lean and HRM practices that differ along the lean process.