To date, little is known about what interventions can help individuals attain leadership roles in organizations. To address this knowledge gap, we integrate insights from the communication and leadership literatures to test debate training as a novel intervention for leadership emergence. We propose that debate training can increase individuals' leadership emergence by fostering assertiveness-"an adaptive style of communication in which individuals express their feelings and needs directly, while maintaining respect for others" (American Psychological Association, n.d.)-a valued leadership characteristic in U.S. organizations. Experiment 1 was a three-wave longitudinal field experiment at a Fortune 100 U.S. company. Individuals (