The purpose of this study was to determine how middle school girls define their comfort in physical education and explore the factors that affect their comfort. The comfort of these middle school girls was studied from the theoretical perspective of Vygotsy's social theory, specifically the interpsychological and intrapsychological processes (Wertsch, 1985). During the adolescent years, youth struggle with themselves and struggle with issues that plague them by others, particularly in social groups, dynamics, and interactions. Participants were 11 seventh grade girls from a coeducational class of 23 students in a circuit-training unit. Data collection included interviews, field note observations, and critical incidents reports (Flanigan, 1954). Data were analyzed using constant comparison (Strauss & Corbin, 1998) to develop categories and subcategories. Findings indicated that the participants interchanged the words fun and enjoyment to define comfort in physical education. These participants also shared experiences and situations in which they did not feel comfortable. The four most prevalent factors that affected their comfort were represented in the following categories: (a) having friends in class, (b) having activity choice and the selection process, (c) participants' perceived competence, and (d) diverse opportunities within physical education. First, participants expressed that having friends in class caused them to have fun thus feel more comfortable. Second, having choice allowed the participants to be in activities that they prefer to participate compared to activities that were selected by the teachers. Moreover, they selected their activities based on what sounded the most fun and the activities their friends shared similar interest. Third, participants' perceived competence affected their comfort in physical education, decisions when selecting activities, and the main characteristic when describing their favorite or least favorite activity. Finally, participants expressed that participating in activities that are not offered regularly, getting to go outside, and selecting activities of their choice were diverse opportunities within physical education that affected their comfort. Collectively, all four factors affect the social influence of the interpsychological and intrapsychological processes. Physical education professionals need to address the issues that affect the physical education environment and the social interactions within that environment prior to tackling how these issues internally affect the students. Thus, knowledge of middle school girls' comfort will allow inservice teachers to consider students' feelings when establishing the societal environment and the social dynamics that will take place within physical education. Keyword(s): curriculum development, middle school issues, physical activity