Relational theories of leadership emphasize the relevance of dynamic changes of informal leadership structures in teams, especially when teams are confronted with new tasks. In this study, we examine how leadership perceptions change in a new task and focus on two potential moderators: interpersonal contact and perceived change in competence allocation. We confronted existing student teams with a new and nonroutine task in the laboratory, during which we assessed team members’ interpersonal face-to-face contact via infrared using wearable sensors. We conducted multilevel analyses focusing on leadership perceptions on the relational level as outcome. Results show that leadership perceptions were relatively stable across tasks. However, team members changed these leadership perceptions more if they had more interpersonal contact with others and if they perceived a shift in competence relations. We discuss theoretical implications regarding informal and shared leadership research and practical implications regarding leadership development, as well as team diagnostics and interventions.