The purpose of this project is to evaluate the effects of a mindfulness-based prosocial skills training curriculum in preschool students with a larger sample in order to replicate and extend findings from initial pilot work conducted in previous years. Participants from the local public school 4-year old Kindergarten program were recruited and participated in pre and post-testing in the 2012-2013 academic year. Students were randomized to either the intervention or a wait-list control group by classroom. Students are currently being followed-up as they transition into Kindergarten for a Time 3 assessment to observe the effects of training over time. The foundation of the Kindness Curriculum is mindfulness practice, aimed at cultivating attention and emotion regulation, with a shared emphasis on kindness practices (e.g., empathy, gratitude, sharing). The preschool Kindness Curriculum is progressive in nature and incorporates children’s literature, music and movement to teach and stabilize concepts related to kindness and compassion. The curriculum is taught by experienced mindfulness instructors in a secular manner and provided universally to children as part of their standard classroom instruction during regular school hours. Student training in the Kindness Curriculum consisted of two 20-30 minute lessons each week over a 12-week period, totaling approximately 10 hours of training.