Purpose Based on the conservation of resources (COR) theory (Hobfoll, 1989, 2002), this study first investigates the direct influence of core self-evaluations (CSEs) on work-to-family (W → F) and family-to-work (F → W) conflicts. Second, it tests the mediating impact of Social support from work and home domains in the associations between CSEs and both directions of work-family conflict. This study finally examines the moderating influence of CSEs in the associations between work and home domain social support and both directions of work-family conflict. Design/methodology/approach Human resources professionals (629), and engineers (169) employed in Canada completed an online survey. Both directions of work-family conflict were measured as well as CSEs, and work and home domain social support. Findings Results indicate that higher CSEs are associated with lower W → F and F → W conflicts. They also suggest an indirect association between CSEs and W → F conflict through supervisor support. The indirect association between CSEs and F → W conflict through home domain social support was also supported. Besides, it appears that CSEs moderate the association between home support and F → W conflict. Research limitations/implications Our findings underscore the relevance of considering both dispositional and environmental factors together in work-life research. Results question within- vs. cross-domain conceptualizations of work-life spillover. They also indicate how both differential choice and effectiveness operate in conjunction with managing work-life domains. Originality/value The research presents a comprehensive model linking work-family conflict, social support and CSEs. It draws from an integrative personality framework (Judge et al., 1998) and COR theory (Hobfoll, 1989) to explore the underlying processes of CSEs, often inferred but not specified or incorporated into work-life research.