Background: University students are considered a vulnerable group due to their adoption of unhealthy diets and lifestyles. Aim: To determine the main risk factors associated with low level of physical activity and excess body weight in university students. Material and Methods: 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. Results: 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). Conclusions: 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.