The purpose of this study was to investigate the effects of coeducational and single gender game play settings on the activity levels of high school physical education students. Participants were 209 students enrolled in six intact physical education classes at an ethnically diverse, low to middle socioeconomic status, Northwestern Florida high school. Three experienced physical education teachers, one female and two males, conducted all physical education classes. Students participated in flag football, ultimate Frisbee, and soccer units. Prior to the start of data collection the teachers and researcher met to discuss class procedures and game rules. Lessons were developed to assure similarity between all classes. Two coeducational classes remained coeducational during game play, two coeducational classes were split into male and female teams for game play, one class was exclusively females-only, and one class was exclusively males-only. Digi-walker pedometers (Yamax SW-701) were worn by students to monitor activity levels over approximately 30 minutes of game play. Activity step counts were converted to steps per minute to account for any variances in the amount of daily game time activity. A series of ANOVA and t-tests were used to test for differences in activity levels. There were no differences in activity levels for females between coeducational and single gender game play settings. Male students were less physically active in males-only than coeducational and coed-split ultimate Frisbee and soccer classes. Data collected using a modified version of a portion of the Observational Recording Record of Physical Educator’s Teaching Behavior (Stewart, 1989) and a survey used to determine the students’ views toward specific team sports and their views toward coed and single gender physical education settings suggest that teacher interaction rates and team sport preferences may have contributed to differences in activity levels, rather than the gender composition of the classes. Overall, issues surrounding coeducational and single gender physical education remain complex. More research is needed that controls for teacher and instructional variability in order to isolate the specific effect of coeducational and single gender physical education on activity levels.Keyword(s): gender issues, high school issues, physical activity