This article examines the masculinization of discipline and its interplay with power in the primary school through an exploration of teachers' gender and disciplinary work and roles by drawing on data from an ethnographic study conducted at a primary school in Taiwan. The research findings suggest that discipline was men's work due to women distancing themselves from discipline, the physical advantages of men and masculinity, and parental expectations. However, negative feelings and pressure towards disciplining were also revealed by men. This research evidence also indicates women were, or could be, as tough disciplinarians as men. More importantly, the masculinization of disciplining work and roles was linked to male domination in power. The teacher workplace culture may help to explain discipline as men's work and power as gendered.