Background: Migrant workers struggle to access health services and adapt to a new culture. Self-care agency can be important for health self-management. It is necessary to investigate in detail how migrant workers engage in health promotion behaviors. This study examines the effects of a health engagement program to improve self-care agency using a living lab approach among migrant workers living in South Korea. Methods: Participants included 42 migrant workers from 9 countries, recruited via flyers, posters, and internet bulletins posted by a migrant community organization. This pilot study used a mixed-methods design including a nonequivalent pre-post-test control group and three focus group interviews. During the 12-week period, only the intervention group participants received four workshops addressing healthy physical activity, healthy dietary habits, effective cultural adaptation, stress management, and two outdoor cultural activities. They also participated in focus group interviews after the second, third, and fourth group activities and discussed the benefits of health behaviors and specific ways to implement them in real life. The control group received no intervention. Results: After the 12-week intervention period, participants in the intervention group showed an increase in the levels of self-care agency (U = 82.5, p < .001), health literacy (U = 91.5, p < .001), and acculturation (U = 119.0, p = .010) compared to the control group. As results of qualitative content analysis, various themes were derived for three areas: healthy diet, acculturation, and stress management based on lessons learned from living lab activities, barriers to health behavior practices and methods to overcome barriers.Conclusions: This study demonstrated that interventions using a living lab were effective in increasing migrants’ participation in health promotion activities by strengthening their self-care agency. The qualitative approach was useful in obtaining more comprehensive results on strategies aimed at enhancing health behavior engagement.