OBJECTIVES:This study sought to determine whether participants in taijiquan classes would report increases in mindfulness greater than that of a comparison group, and whether changes in mindfulness were associated with improvements in mood, perceived stress, self-regulatory self-efficacy, and sleep quality. DESIGN: The study design was quasi-experimental with repeated measures. SETTINGS/LOCATION: The study was set in a midsized public university. SUBJECTS: Students aged 18-48 years old enrolled in 15-week courses of either taijiquan (n=76) or special recreation (control group, n=132). INTERVENTION: Chen-style taijiquan classes were offered 2 times per week for 50 minutes each time. OUTCOME MEASURES: Self-report of mindfulness (Five Facet Mindfulness Questionnaire), mood (Four Dimensional Mood Scale), perceived stress (Perceived Stress Scale), self-regulatory self-efficacy (Self-regulatory Self-Efficacy Scale), and sleep quality (Pittsburgh Sleep Quality Index). RESULTS: Increases in total mindfulness scores occurred only in the taijiquan group, not in the control group. All well-being variables showed a pattern of improvement in the taijiquan group, with either stability or decline over time in the control group. Increases in mindfulness were significantly correlated with improvements on all well-being measures and with sleep quality. CONCLUSIONS: Relative to a recreation control group, taijiquan classes for college students are associated with increased mindfulness and improved sleep quality, mood, and perceived stress, but not self-regulatory self-efficacy. Randomized control design studies are needed to substantiate the causal role of taijiquan exercise in the development of mindfulness and associated improvements in well-being.