This article explores whether and how labour law matters in factory workers' grievances and demands in their letters sent to the unions and state authorities in Dong Nai Province, an industrial hub in the south of Vietnam. An examination of the letters demonstrates that the legalistic language of rights and other provisions in the Labour Code plays little role in shaping workers' accounts. A majority of letter writers instead referred to moral aspects of subsistence, reciprocity, and their subjective views of fairness to make their claims. Yet the moral constructions of workers' claims may overlap and derive from values imbricated within the Labour Code. These observations raise the need to consider the subtle way in which law generates workers' resistance against management and/or the state, as well as the fluid boundary between law and morality in workers' narratives of (in)justice.