Approximately 1/3 of the children in the United States are overweight or obese. Children in Mississippi have the highest rate of obesity among all other states. The outcome of this epidemic presents an increase in poor health. To address the problems associated with overweight and obesity among children, schools in the U.S. were required to develop school wellness policies. School principals were identified as key individuals in overseeing the development and implementation of the policies. Existing research studies show a strong relationship or association between student health and academic achievement. The purpose of this research study was to investigate elementary school principals' perceptions related to the implementation of school wellness policies. The study sought to examine principals' perceptions regarding physical activity, child nutrition, health education, and general beliefs about school health policy implementation. A web-based survey was sent to 670 elementary school principals with 123 (18%) responding. The majority of the respondents were White females who had served four or more years as principals, had average enrollments of 500 students at their schools, and had school ratings of successful or high performing. Positive weak correlations were found to exist between school accountability ratings and principals' beliefs that physical activity promotes improved test scores and that physical activity and healthful nutrition promote increased school attendance. Positive weak correlations were also found between school accountability ratings and principals' beliefs that physical activity, child nutrition, and health education promote improved classroom behavior. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]