The purpose of this study was to determine the effects of a single bout of yoga on happiness, self-esteem, and self-efficacy for exercise in a volunteer sample of 25 college students from a public university in southeastern United States. Previous research explored long-term effects of yoga on mental health, but the effects of a single bout of yoga are unclear. Volunteers from a summer-session yoga course completed 26 items on demographics, happiness, self-esteem, and self-efficacy for exercise, before and after their first 30-minute yoga session. Paired samples t-test showed no significant differences in pre- and posttest scores of measured variables: % happy (M=62.7; M=62.9; p=.976), % unhappy (M=23.2; M=25.1; p=.662), % neutral (M=33.5; M=30.6; p=.650, self-esteem (M= 28.8; M=29.6; p=.721), and self-efficacy to exercise (M=16.0; M=17.4; p=.292). Although no significance was found, future research should focus on the impact of yoga (both single-bout and long-term effects) on health variables in a larger sample, and within diverse populations. Future research should also consider the effects of other exercise protocols, including steady state aerobic, high-intensity interval training, and resistance training.