question: Background: The COVID-19 pandemic has affected the health behaviors of university students Thus, factors influencing students' health behaviors during the COVID-19 outbreak should be examined Purpose: To our knowledge, little is known about stress, adversity quotient, and health behaviors of university students in Thailand Therefore, the aims of this study were to determine the relationships among socioeconomic factors, stress, and adversity quotient influencing university students' health behavior during the COVID-19 crisis Patients and Methods: We conducted a cross-sectional predictive study;it was included 416 undergraduate students &gt;= 18 years of age at a university in Thailand We used descriptive statistics, chi-squared test, and stepwise multiple linear regression for data analysis Results: The results indicated that most participants were women (71 90%), and the highest proportion of students were enrolled in College of Politics and Governance (25 24%) Most of the students had a high stress level (M = 3 54, SD = 0 53), high adversity quotient (M = 3 77, SD = 0 63), and good health behavior (M = 3 06, SD = 0 53) Adversity quotient, stress, and current faculty/college were significant predictors of health behaviors of undergrad students (total variance: 37 2%) Conclusion: Total adversity quotient was the strongest predictor of health behavior, followed by stress and current faculty/colleges On the basis of our results, we suggested that faculty members, caretakers, and interdisciplinary care teams should consider adversity quotient and stress in developing activities to encourage and promote students' physical and mental health behaviors, particularly during the COVID-19