Objectives: University students experience heightened levels of stress and are seeking mental health services with increasing frequency. Mindfulness-based interventions (MBIs) may be an effective resource for managing stress. The present study examined the effectiveness of an MBI in reducing stress, anxiety, and rumination compared to active and traditional control conditions. Methods: Undergraduate students at a southeastern university participated in either a 4-week MBI, active control, or traditional control condition. Measures were collected pre- and post-intervention. Results: Overall the MBI had a significant impact on perceived stress over and above both traditional and active control conditions. The MBI also had a significant impact on trait mindfulness and anxiety compared to the traditional control condition. No significant differences were observed for rumination. Conclusions: The MBI significantly impacted trait mindfulness, perceived stress, and state anxiety. MBIs may be a useful approach to successfully alleviating stress in a highly stressed population.