This article describes a narrative study exploring the challenges that international teaching assistants (ITAs) encounter when using humor in North American university classrooms. Twenty participants were recruited from twelve teaching fields. Each ITA participated in two interviews and a videotaped teaching observation. The participants talked about their use of humor in the classroom and the reasons they were reluctant to engage in humor. These autobiographical narratives were then subjected to thematic analysis (Braun & Clarke, 2013). Findings from this study revealed that the ITAs specified linguistic, cultural, social, and authoritative challenges to using humor, but then explore the ITAs' personal strategies to overcome these obstacles. The article concludes with a discussion of how humor can benefit ITA training programs and provide a way to explore the connections between language, culture, and pedagogy.