BACKGROUND: This study aimed to examine the effects of nurses' work-life balance (WLB), job demands and resources, and organizational attachment on their work engagement (WE). The second aim was to shed light on whether the relationships among WLB, job demands, resources, and WE are modulated by organizational attachment. METHODS: In total, 425 nurses working in a university hospital responded to the questionnaire. The primary statistical analysis method was hierarchical multiple regression with WE as the dependent variable. RESULTS: In the model in which all variables were applied, affective commitment (AC) (β = 0.41), family-to-work positive spillover (β = 0.25), and number of children (β = 0.13) were found to have a significant association with WE. Family-to-work negative spillover (FWNS) and AC had significant interaction effects. The result suggests that when AC was low, WE tended to decline further due to FWNS; however, when AC was high, WE did not change due to the effect of FWNS. CONCLUSION: These results confirmed that to improve nurses' WE, hospital organizations should implement initiatives to facilitate WLB that considers nurses' household roles. Furthermore, high organizational attachment buffered the home's negative influence on work, thereby helping nurses work energetically.