The Balanced Energy Physical Activity Toolkit, or the BEPA-Toolkit, supports physical activity (PA) programming via Extension in elementary schools. In a pilot study, we evaluated the effectiveness of the BEPA-Toolkit as used by teachers through Supplemental Nutrition Assistance Program Education partnerships. We surveyed teachers (n = 57) regarding their use of the kit and examined associations between teacher use of the kit and objectively measured PA of students (n = 1,103). Over 80% of responders reported that the BEPA-Toolkit provided additional opportunities for PA, and children regularly exposed to the kit were more active than those having less exposure to it. The BEPA-Toolkit may support PA opportunities in underresourced school settings.