The present study advances research on the negative consequences of precarious work experiences (PWE), which include perceptions of threats to one's job and financial security as well as a sense of powerlessness and inability to exercise rights in the workplace. Using the COVID-19 pandemic as a backdrop, we examine how PWE relate to sickness presenteeism and worry about work-related COVID-19 exposure. In a 12-week, four-wave study of workers working fully in-person, perceptions of powerlessness and job insecurity were associated with presenteeism (e.g., general presenteeism as well as attending work with known or possible COVID-19 infection) and concerns about disease exposure at work. Whereas powerlessness primarily operated at the between-person level of analysis, job insecurity's effects emerged at both levels of analysis. A sense of powerlessness at work also predicted sending children to school/daycare sick. In sum, the findings suggest that precarity related to being able to keep one's job and a sense of powerlessness at work contribute to concerns about the risk of COVID-19 exposure at work and, simultaneously, behaviors that may contribute to the health risks faced by others. This research provides added support to the argument that precarious work should be addressed in order to improve both worker well-being and public health.