This article describes impromptu presentations, a new pedagogical approach for college classrooms that produces full engagement and rapid information processing by students. The technique offers an additional tool to the growing literature on active and collaborative learning. Given a short timeframe, students are required to investigate, analyze, or solve problems assigned by the instructor. This brief critical thinking phase is followed by group presentations in which the students must support their arguments and teach others about relevant course concepts. The traditional idea of learning by teaching serves as the foundational principle behind this approach. Various ways of employing impromptu presentations in the classroom are also described. Finally, the merits of the impromptu presentation approach are highlighted by drawing on the active learning, peer teaching, and levels of learning literature streams.