This article inquires into the role of humor in the relational learning process that takes place in adventure education programs. It presents program episodes, which the authors experienced in their practice as facilitator, staff trainer and researcher, and explores the related literature. Four aspects appear to affect whether humor either facilitates or interferes with participants' learning in development programs. First, humor plays a role in developing relationships among participants and between participants and facilitators, and hence in the relational safety that characterizes an environment conducive to learning. Second, it may play a role in creating a workable distance to sensitive learning issues. Third, humor may offer new and unexpected perspectives, which contribute to revising familiar but restrictive reference frames. Finally, humor seems to fulfill these functions to the extent that it is not planned to do so, and as such may exemplify the 'paradox of functionality' in relational processes. (Contains 2 figures.)