The primary purpose of this study was to determine the relationships between selected teacher behaviors and interactions provided to girls and boys in middle school physical education classes and the students’ affective outcomes. A second purpose was to compare the differences in teacher behaviors provided to students and the affective outcomes of girls and boys by gender of the teacher. A final purpose was to compare the differences between girls and boys affective outcomes. The subjects in this study were 14 female and 14 male volunteer physical education teachers from 12 different public middle schools in Northern Colorado. The teachers taught individual, team, and non-traditional activities in a co-educational setting. There were 604 student subjects, 281 were girls and 323 were boys. The design of the study included observations of teacher and student interactions during class and students’ responses to questionnaires. Questionnaire were used to measure students’ affective outcomes of attraction to physical activity, attitude towards physical education, self-esteem, physical activity enjoyment, and physical self-efficacy. Nine teacher behaviors were coded live during two observations of each teacher during class. Pearson Product Moment Correlations were used to determine relationships between teacher variables and student variables. Few significant relationships were found between teacher behaviors and students’ affective outcomes. However, significant relationships did exist between four teacher behaviors and four affective outcomes for female students. The only significant relationship between teacher behaviors and affective outcomes of male students was between nonverbal interaction and enjoyment (r=.42). Multiple Analysis of Variance (MANOVA) was used to determine differences between teacher behaviors by gender. No significant differences were found between the behaviors and interactions provided by all teachers to female and male students. No significant differences were found between the teacher behaviors provided to boys and girls by female teachers. One significant difference was found between feedback provided by male teachers and the student groups. Male teachers provided disciplinary interactions to male students significantly more than to female students (F=10.59, p < .05). MANOVA was also used to determine that significant differences were found between the affective outcomes of girls and boys in middle school physical education. The girls’ enjoyment of physical activity and physical self-efficacy were significantly lower than for boys.