In the context of Industry 4.0, research on lifelong learning intention (LLI) and adoption is valuable for developing a learning society. However, prior studies on LLI of adults have primarily focused on the impact of individual characteristics or environment sporadically. There is a lack of research approaching LLI of adults. In emerging markets like Vietnam, although lifelong learning is an essential competence, scholars have not focused on this issue. Therefore, this study has built a path model to explain factors affecting the LLI of Vietnamese adults in the business sector by integrating individual and social antecedents forming LLI. We empirically analyse the data obtained through a survey of 417 adults. The findings that are established using SmartPLS certify that attitude, social influence, perceived behavioural control, voluntariness and self-efficacy are significant determinants of both the perceived usefulness of lifelong learning (PUoLL) and LLI of adults. While jobs relevant in the business sector have impacted PUoLL, it is not directly the relation to LLI. The study establishes a strong positive influence of PUoLL on the LLI of adults in the business sector. The results provide important insights for policymakers, educators, scholars and learners to develop strategies for lifelong learning for adults.