University students are considered a vulnerable group due to their adoption of unhealthy diets and lifestyles. To determine the main risk factors associated with low level of physical activity and excess body weight in university students. This cross-sectional study included 358 university students from Talca, (53% female). Sociodemographic, academic, health, lifestyle, nutritional status, physical activity and sedentary behavior variables were analyzed by logistic regression. Men were more likely to present excess body weight than women (Odds ratio (OR): 2.16 [95% CI: 1.17-4.01], p = 0.01). Similarly, those with low level of physical activity (OR: 2.13 [95% CI: 1.10-414], p = 0.03), musculoskeletal injuries (OR: 2.43 [95% CI: 1.09-6.34], p = 0.05) and smokers (OR: 2.09 [95% CI: 1.05-4.14], p = 0.04) were more likely to have excess body weight. Individuals with excess body weight (OR: 2.94 [95% CI: 1.31-6.61], p < 0.01), high sedentary behaviors (OR: 2.01 [95% CI: 1.04-4.55], p = 0.04), those who spent more than 7 hours per week studying (OR: 2.11 [95% CI: 1.06-4.66], p = 0.04), and those with presence of musculoskeletal injuries (OR: 1.49 [95% CI: 1.06- 3.66], p = 0.04) were more likely to be physically inactive. In addition, men were 73% less likely to have low physical activity levels compared to women (OR: 0.27 [95% CI: 0.11-0.56], p < 0.01). University students have several modifiable risk factors associated with low levels of physical activity and excess weight. Healthy lifestyles promotion should modify these risk behaviors.