“Emergent leadership”—the ascription of informal leadership responsibilities among team members—is a dynamic phenomenon that comes into place through social interactions. Yet, theory remains sparse about the importance of verbal behaviors for emergent leadership in self-managed teams over a team’s lifecycle. Adopting a functional perspective on leadership, we develop a temporal account that links changes in task-, change-, and relations-oriented communication to emergent leadership in early, middle, and late team phases. We test the hypothesized relationships in 42 teams that provided round-robin emergent leadership ratings and videotapes of their first, midterm, and final meetings. Team members’ verbal behaviors were captured using fine-grained empirical interaction coding. Multilevel modeling showed that task-oriented communication was a stable positive predictor of emergent leadership at all time points. Change-oriented communication predicted emergent leadership at the start of a project and diminished in relevance at the midterm and final meetings. Relations-oriented communication gained importance, such that an increase in relations-oriented behaviors toward the project end predicted emergent leadership. We discuss theoretical implications for conceptualizing the behavioral antecedents of emergent leadership from a time- and context-sensitive perspective.