The first year of university study provides an ideal opportunity to target student participation in many health behaviors such as recreational sport. The study used the theory of planned behavior to identify the key behavioral, normative, and control beliefs underlying student participation in recreational sport. A cross-sectional design was used with a 4-week follow-up. A purposive sample of 206 participants responded to a theoretically informed questionnaire measuring baseline cognitions. Follow-up behavior was measured using self-report questionnaires. All beliefs correlated with intention, and seven beliefs correlated with behavior. Four key beliefs predicted intention (“enjoyable,” “time consuming,” “friends,” and “family members”) and two key beliefs predicted behavior (“enjoyable” and “time consuming”). Interventions successfully targeting these specific beliefs may lead to a greater number of students participating in recreational sport.