Teaching has been identified as the most stressful profession in the human service industry (Greenberg in Teacher stress and heal the effects on teachers, students, and schools, Edna Bennett Pierce Prevention Research Center, Pennsylvania State University, University Park, 2016). Elevated teacher stress not only affects the teacher’s well-being and likelihood of burnout, but also the classroom climate of young children. The purpose of the present study was to assess whether mindfulness practices can increase positive classroom climate and decrease perceived stress in early childhood teachers. Participating teachers were selected based on results of the Perceived Stress Scale (PSS, Cohen in Journal of Health and Social Behavior, 24:285–396, 1983). Data were collected on the positive and negative climate objectives from the Classroom Assessment Scoring System (CLASS; Pianta in Classroom assessment scoring system (CLASS) manual, pre-K, Paul H. Brookes Pub. Co., Baltimore, 2008), which were operationally defined. The Mindfulness Practices Intervention included yoga poses, intentional breathing, and guided mediation (Harris in Mindfulness 7:143–154, 2015), which were implemented within the school day during arrival, mid-morning, lunch, mid-afternoon, and after work in the evening. Perceived Stress Scale scores decreased for two of the participating teachers; all three teachers’ increased positive climate and decreased negative climate. Results of the current study suggest that this low-cost, low labor-intensive intervention was effective in improving classroom conditions for both teachers and young children. (author abstract)