“Cross-sector collaboration on child obesity prevention is common, yet little research has examined the context of collaboration at the state level. This study describes secular trends in collaboration between state agency staff responsible for school nutrition and physical education activities and other organizations from 2000 to 2012. Data from the School Health Policies and Practices Study were used to describe collaboration between state agency staff and 13 types of public, private, and nonprofit organizations. Breadth of collaboration in 2012 was examined across political, social, and economic conditions. Collaboration between state agency staff and other organization types increased from 2000 to 2006 and decreased or stabilized from 2006 to 2012. Breadth of collaboration was greater in states with a physical education coordinator, higher levels of poverty, higher prevalence of childhood obesity, and more public health funding. Breadth was similar across states by census region, political party of governor, majority party in state legislature, percentage non-Hispanic white population, high school graduation rate, and unemployment rate. Cross-sector collaboration on school nutrition and physical education was widespread and did not vary substantially across most political, social, and economic measures. Expanded monitoring and surveillance of state-level collaboration would assist efforts to understand how state agencies work across sectors and whether this collaboration affects the support they provide to schools.”