This article seeks to test whether a leader's position in the team's informal network strengthens or weakens the leader's team. Based on data collected from 231 employees working in 19 teams in a manufacturing organization, the study tested whether two different leader network centralities in teams' advice networks predicted team conflict and viability. Teams with more prestigious formal leaders (i.e., leaders whom a high proportion of subordinates sought out for advice) experienced lower levels of team conflict and had higher levels of team viability. In contrast, teams with leaders who brokered across subordinates within a team's advice network (i.e., leaders who had advice ties with subordinates who did not have advice ties with each other) reported elevated levels of team conflict and lower levels of team viability, even when controlling for the team leader's prestige. Team conflict mediated the effects of the two leader network positions on team viability.