Annual evaluations of the Mississippi Healthy Students Act of 2007 (MHSA) were conducted from 2009-2011 among four stakeholder groups: (1) parents of public school students; (2) adolescents; (3) school officials (e.g., superintendents); (4) state-level policymakers (e.g., legislators). We examine results from the first state-wide study among a randomized sample of parents (N>3,600 per year) on childhood obesity as it related to MHSA. Parents were surveyed to determine: (1) knowledge/attitudes towards MHSA; (2) knowledge/attitudes/behaviors (KAB) that influence children's health; and (3) perceived overweight/obesity of self and child versus BMI-determined overweight/obesity. Across all three years, parents were very supportive of MHSA across a number of variables, while parents greatly underestimated obesity among self and child when compared to their BMI data. Results highlight complexities of parents' KAB that potentially influence children's health, including the MHSA. Policy implications are discussed.