Mindfulness is the practice of being nonjudgmentally aware of the present moment. Researchers often study the effects of mindfulness using brief laboratory-based mindfulness inductions in which participants are guided through mindfulness exercises, after which outcome measures are examined. However, most studies have not assessed whether participants achieved a mindful state during the induction, or whether the effects of mindfulness inductions differ from the effects of similar procedures such as relaxation. The present study compared a mindfulness exercise to a relaxation exercise and a control condition. After the induction, participants completed measures of the extent to which they attained a mindful state. Trait-levels of mindfulness, rumination, and openness were measured prior to the induction to test for moderating effects. Results revealed that the mindfulness induction led to higher state mindfulness scores than the control induction, but did not lead to higher scores as compared to the relaxation induction. No significant trait moderators were found. Findings suggest that brief mindfulness interventions may not be sufficient to induce a truly mindful state in a non-meditating sample. Findings also bring into question the results of studies that do not include a manipulation check post- induction, as well as the utility of self-report measures of state mindfulness in nonmeditating student samples