University is a pivotal point in life for physical activity (PA) behaviour because decisions made at this time may lead to an active life in later adulthood, or transition to a sedentary lifestyle. The purpose of this study was to identify differences between men and women with high and low task self-efficacy (SE) in their perceptions of how environmental factors (ex. Others flexing/posing, mirrors) within a gym influence their use. To test this, 703 university students (543 women; 160 men) provided responses to an online survey including questions regarding demographics, their exercise task-SE, and how environmental factors influenced their gym use. Differences on the 33 environmental factors were tested using 2X2 ANOVAs. A significant main effect for gender (all p’s < .05, η;2 = .01 to .04) was found for 18 environmental factors, and a significant main effect for task self-efficacy (all p’s < .05, η;2 = .01 to .05) was found for 27 environmental factors. Additionally, a significant interaction effect was found for one environmental factor (Loud people; F(1, 699) = 8.09, p < .01, η;2 = .01). Taken together, our results show men with high task-SE generally had a more positive perception of physical and social environmental factors compared to men with low task-SE and women. Whereas women with low task-SE generally reported more negative perceptions of environmental factors. The results suggest targeting people’s task-SE (especially women) may be important for enhancing perceptions of the gym environment and promoting subsequent use of the facility.