Background: Obesity is a public health concern that disproportionately affects underserved and minority communities. Purpose: To evaluate whether a comprehensive obesity prevention program that targets children and school staff in an underserved Hispanic community affects obesity related knowledge, attitudes, and behaviors among both students and staff. Methods: Using a longitudinal design over 2 years we administered surveys to fourth-grade students (N = 184) and school staff (N = 99) from 7 elementary schools involved in a comprehensive obesity prevention program. In year 2, a control group of students and staff from a neighboring school completed the same surveys for comparison. Results: Over 2 years, students and school staff participating in the program reported improved nutrition knowledge and behavior, and school staff reported improved self-efficacy for physical activity and a trend toward increased physical activity. In year 2 student nutrition behaviors improved preferentially for intervention versus control students. Discussion: Comprehensive programs that target students and school staff may be useful in underserved communities to improve certain knowledge, attitudes, and behaviors related to nutrition and physical activity. Translation to Health Education Practice: Working in concert with public health policy changes, these programs may help to address the disparity in the obesity rate.