PurposeSupporting employees’ work–life balance (WLB) has been a standard human resource management practice, thus the concern is now shifted toward its outcomes. The present study predicts that while WLB can boost organizational citizenship behaviors (OCBs), this positive effect may depend on the quality of leader–member exchange (LMX) relationships. The study seeks evidence to clarify how the WLB–OCBs relationship can be moderated by the LMX quality.Design/methodology/approachA sample of 216 frontline employees in New Zealand was used to test two moderation models using SPSS, AMOS and PROCESS macro.FindingsWLB was found to have substantial effects on OCBs-individual (OCBs-I) and OCBs-organization (OCBs-O) if the quality of LMX was high. Under low LMX quality, however, WLB failed to boost OCBs-I and OCBs-O. Thus, the influence of WLB on OCBs seems to be conditional on the leader–subordinate relationship as a boundary factor.Practical implicationsSupporting low-LMX-quality employees to balance their work–life roles seems insufficient to push OCBs. Managers and organizations need to improve the quality of leader–subordinate relationships to unblock the desired effects of WLB toward OCBs, and, ultimately, organizational effectiveness and performance.Originality/valueThe findings extend the research stream around the boundary impact of LMX relationships on the employees’ WLB – OCBs link in which the OCBs construct was especially examined in terms of OCBs-I and OCBs-O.