The literature has predominantly focused on the positive effects of leader boundary-spanning behavior, but its potential costs should also be given serious consideration. Drawing from the work-home resources model, we investigated the ways in which boundary-spanning behavior influences both boundary-spanning leaders themselves and their spouses. Using daily diary data collected from 75 matched couples in China over 10 consecutive workdays, we performed a multisource, multilevel research design. The results suggest that leader boundary-spanning behavior appears to have positive relationships with leaders’ work-to-family conflict and their spouses’ perceived family incivility via ego depletion. We also found that two related factors – boundary-spanning self-efficacy and manager support for boundary-spanning behavior – play significant mitigating roles in this context. These results suggest that effort is needed to balance the benefits of leader boundary-spanning behavior with the corresponding challenges, including individual depletion and detrimental family outcomes.