This quantitative study examined the characteristics of the developmental networks of young South Korean self-initiated expatriates (SIEs) in Vietnam and the effects of the network characteristics on developmental functions and career growth. Based on a literature review, a hypothesized model was developed and examined using a path analysis. The results demonstrated that organizational, cultural, and program diversity and network strength influenced different types of developmental functions (career, psychosocial, and cultural support). The findings also demonstrated that cultural support did not have a direct relationship with perceived career growth opportunities, while it indirectly influenced career growth through career and psychosocial functions of developmental networks. This study provides a comprehensive understanding of SIEs' developmental networks and their effect on career development with empirical evidence. The results of this study will inform career counselors and educators on how to support SIEs' career development and career-related relationship building.