Physical inactivity poses concern for health risks among all groups in the United States. Active transportation (AT) (e.g., bicycling) is one way of being physically active and may be helpful in promoting physical activity. This study characterized active transportation behavior among college students using the Theory of Planned Behavior. This study sought to describe predictors, including Theory of Planned Behavior (TPB) constructs, of AT behavior among college students at a large Midwest university. Students were recruited through the university registrar's office and e-mailed an electronic survey. Differences among AT users were determined using t-tests, and predictors of AT were identified using regression analysis. Significant differences between AT users for all TPB constructs were observed. Regression analysis using only TPB constructs accounted for 11.58% explained variation in AT use. Other variables added to the model resulted in 44.44% explained variation in AT use. The final model included subjective norms, age, perceived behavioral control, and transportation type and destination. The results of this research are insightful in explaining AT behavior. Perceived norms and the level of control students had regarding their method of transportation were important contributions to AT use. These results may be applied to promoting physical activity in community health.