Facing labor shortages and looming economic challenges, East Asian countries decided to open their labor markets and recruit low-skilled foreign workers. For example, Taiwan adopted a guest-worker program in 1992 that heavily involved private recruitment agencies as labor mediators, whereas Korea launched a temporary labor migration program in 2003 through government-to-government agreements. Despite their similar democratic experiences and developmental histories, why has Korea developed a government-managed guest-worker program while Taiwan has established a brokerage-driven program to control foreign workers? What are the driving factors behind the divergence of labor migration governance between Taiwan and Korea? To answer the question, this paper first compares key features of their foreign labor policy, including recruitment, admission, employment, and return of migrant workers, and then examines the main drivers behind the institutional divergence. This study argues that three factors have largely determined the divergent outcomes of labor migration policies: (1) the power balance between economic and social ministries in the government, (2) political pressures from civil society for migrants’ rights, and (3) systematic participation of labor unions in social movements for labor migrants.