Career indecision is a substantial challenge for multicultural adolescents in South Korea. This study investigated the role of acculturation stress in adolescents and their parents in multicultural families on career decisions in South Korea. Perceived career barriers by adolescents and career-related behaviors of their parents were included as mediators. Using national panel data from 1695 cases longitudinally collected over the 3 years, the mediation analysis was conducted. The results showed that acculturation stress experienced by both adolescents and parents negatively predicted the adolescents' career decisions. In addition, a sequential mediation effect of parental career-related behaviors and adolescents' career barriers was found in the relationship between parental acculturation stress and adolescents' career decisions. These results highlight the importance of acculturative stress experienced by families, and not just by individuals, in understanding the career development of multicultural adolescents. The implications of this study's findings are discussed.