This study evaluated the effectiveness of a mindfulness-based yoga intervention in promoting self-regulation among preschool children (3–5 years old). Twenty-nine children (16 intervention and 13 control) participated in the yearlong study that used a quasi experimental pretest/posttest treatment and control design. The mindful yoga intervention was implemented regularly by the classroom teacher for the treatment group. Treatment and control participants completed evaluations that assessed multiple indices of children’s self-regulation (i.e., attention, delay of gratification and inhibitory control) using a combination of parent report and direct assessments. Results from the direct assessments indicated significant effects of the intervention across all three indices of self-regulation. There was also some evidence that the children who were most at risk of self-regulation dysfunction benefited the most from the intervention. Implications of this study for current practice in early childhood education are discussed along with possibilities for future research in this area.