Psychological capital (PsyCap) plays an important role in increasing the learning capacity, professional skills, problem-solving, and innovation in the work of employees (Luthans et al., 2013). In developing countries, for example, Vietnam, research on PsyCap has not been mentioned much or fully. It extends beyond social capital and human capital to create profitability. The objective of this paper is to study the impact of PsyCap on the work engagement of sales staff in real estate enterprises in Vietnam. PsyCap includes the factors: 1) confidence, 2) optimism, 3) hope, and 4) resiliency. The research method we used is quantitative, with a sample size of 453 real estate sales staff in Vietnam. The research model is based on the theory of PsyCap and work engagement. The results of the study showed that resiliency had the strongest impact on dedication and passion at work, while confidence and optimism also had a positive effect, but to a lesser extent. However, factors such as hope did not have a significant impact. The study provides practical suggestions for real estate firms in developing training programs to enhance employees’ PsyCap to increase engagement and work performance.