This study explores the use of mindfulness school-based intervention program in an elementary school. Mindfulness training is an accepted and effective didactic approach to improve the executive functions (EFs) of elementary school students. This study aimed to evaluate the effects of the Mind Yeti program on the executive functions of elementary school students. A diverse sample of third, fourth, and fifth grade elementary school students (n = 177) participated in their natural classroom setting, with six sessions per week for six weeks. Students self-reported their EFs on the Executive Function Student Questionnaire (EFSQ) pre- and posttest. Paired-sample t-tests indicated that students significantly improved on the three of the six EFs examined. Additionally, students in fifth grade responded better to Mind Yeti than students in third grade. Results were consistent with the hypothesis, suggesting that Mind Yeti is an appropriate and effective intervention for improving the EFs of students.