An estimated 12.5 million American children and teens are obese. Over time, the diseases and disabilities associated with obesity may undermine this population's health and result in substantial social and economic costs. Policies that address children's nutrition and physical activity are an important tool in reversing the obesity epidemic. More states are developing such legislation, but little is known about the factors that influence passage or how the resultant policies relate to childhood obesity rates. Having that knowledge could help public health advocates target policy interventions more effectively. From April 2009 to September 2011, researchers at the Prevention Research Center in St. Louis, a joint venture of Washington University in St. Louis and St. Louis University analyzed state legislation on childhood obesity enacted from 2006 to 2009 to identify patterns in the topics addressed, the presence of evidence-based components, and factors that predict successful enactment. Project staff reported the following findings: (1) The 10 state legislation databases examined showed substantial variation in their comprehensiveness and in their strengths as research tools, ease of use, and cost; (2) Few state-level factors predicted enactment of childhood obesity legislation; (3) Bills that addressed safe routes to school or health or nutrition education in schools were twice as likely as other bills to be enacted; and (4) Policymakers and advocates have different perspectives on childhood obesity policy as a problem or priority. A bibliography is included. (Contains 8 footnotes.)