Research suggests that second/foreign language teachers' sense of humor is directly related to many outcomes for teachers and their students. This research investigates the relationship between the perceived sense of humor of in-service Spanish teachers' (n = 102) and their students' (n = 5,419) score on the National Spanish Exams using the affective filter hypothesis as a conceptual framework. Statistical analyses indicate that Spanish teacher sense of humor is related to student achievement on the exams. This research has implications for language teachers and teacher educators.