This paper investigates the effect of work-from-home (WFH) on work-to-family spillover (WFS) and employees’ in-role job performance (IRJP) while also exploring the moderating effect of emotional intelligence (EI). Data were collected using questionnaire survey, including a sample of 159 Vietnamese respondents living in Vietnam and having WFH experience. Data analysis techniques include measurement tests and regression analysis for hypothesis testing using SPSS software. The findings indicate that WFH significantly enhances positive work-to-family spillover (PWFS) and WFS has a notable impact on IRJP. Specifically, PWFS enhances IRJP by encouraging outward-focused thought-action patterns, whereas negative work-to-family spillover (NWFS) reduces IRJP by promoting inward-focused thought-action patterns. Nevertheless, the direct influence of WFH on IRJP and the moderating role of EI could not be verified. Theoretically, this study enhances JD-R theory and broaden and build theory by demonstrating that WFH serves as a resource positively influencing PWFS and confirming the significant impact of WFS on IRJP. Practically, the paper suggests that organizations should adopt WFH practices and focus on some human resource management policies to enhance PWFS and decrease NWFS, thereby boosting employee performance.