Using Scanlan and Lewthwaite's (1986) sport enjoyment model as a conceptual framework, this study was designed to explore two areas: (a) students' and teachers' perceptions of "fun" in physical education class and (b) differences that may exist in these perceptions between groups of students (in team sports, individual/dual sports, and fitness) and teachers. The critical incident technique and a fun survey were administered to 191 participants. Critical incident technique narratives and descriptive statistics revealed the importance of achievement motivation concepts, such as teacher, task, and the social aspects of fun in physical education, whereas MANOVA revealed significant differences in perceptions of fun between students and teachers. (Contains 2 tables.)