Entrepreneurship has become an important topic for governments to shape and influence the quantity and quality of entrepreneurship and improve policy toward the entrepreneurial economy. This study investigates the factors affecting the entrepreneurial decision of nascent entrepreneurs belonging to Generation Y in Vietnam. A mixed-method including both qualitative and quantitative methodologies was utilized. A focus group was carried out with 11 participants for exploring, reviewing, and testing content validity of constructs and measurement items. The conceptual model and hypotheses were developed using data collected by a questionnaire survey. The cross-sectional survey method was applied. A sample of 221 respondents was constituted, by both electronic and paper surveys with non-probability and convenience sampling techniques. SmartPLS 3 software was employed to analyze the data collected. The results show that nine factors were affecting the entrepreneurial decision of nascent entrepreneurs belonging to Generation Y in Vietnam, including entrepreneurial education, family background, entrepreneurial ecosystem, perceived behavioral control, social valuation, perceived opportunity, attitude, entrepreneurial self-efficacy, and entrepreneurial intention. The findings show the importance of entrepreneurial education, social value, and ecosystems. Therefore, in order to promote successful entrepreneurship, it is necessary to strengthen entrepreneurship education and have a strategy for the improvement of the entrepreneurship ecosystem.