OBJECTIVES: This descriptive research was aimed at examining the predicting factors of physical activity among university students. MATERIAL AND METHODS: Four hundred undergraduate students at Burapha University, Bangsaen campus, were invited to participate in this study. Data were collected by using questionnaires and multiple linear regressions statistic was used for analyzing the predicting factors of physical activity. RESULT: The research findings revealed that 41 percent of the research participants had a high level of physical activity. Their perceived self-efficacy (ß = 0.43, p < 0.01), interpersonal influences (ß = 0.19, p < 0.01) and perceived benefit (ß = 0.14, p < 0.01) were the significant predictors of physical activity, accounted for 37.9 % of the variance. CONCLUSION: Encouraging young adults to take care of their own health and motivating them to engage in physical activity organized by university health promotion agencies would finally result in their health benefits. Strategies targeted at physical activity, perceived self–efficacy, interpersonal influences and perceived benefit of physical activity should be developed for promoting behaviors of physical activity and exercise.