Objective: "MyPlate," a tool for communicating the federal nutrition guidelines in the USA, may contribute to healthy diets and behaviours, yet whether and how it is used by teachers and school principals is unknown. The purpose of this study was to examine (1) the prevalence of using nutrition lessons and MyPlate guidelines by K-12 teachers and principals; (2) barriers to, and facilitators of, using them; and (3) suggested strategies to improve their use. Methods: A convenience sample of teachers and principals (n = 124) from a Midwestern US school district were surveyed. Results: The majority of respondents were women (88%), elementary school teachers (76%) and Caucasian (90%). A total of 18% (n = 16) of teachers included nutrition in lesson plans. A total of 17% (n = 15) of teachers used MyPlate in their classrooms, primarily through handouts and group activities. Being a parent and being more familiar with MyPlate were positively associated with including nutrition in lessons, and income and higher education were inversely associated with including nutrition in lessons. Barriers included lack of time, knowledge and resources, and facilitators included believing nutrition was important, nutrition being part of the curriculum and personal interest. Suggested strategies to improve use of MyPlate included introducing the MyPlate curriculum into health, physical education or other classes; using MyPlate messages in the cafeteria; and posting signage around the school. Conclusion: MyPlate use was low in this sample of teachers and principals in a Midwestern US school district. Handouts, group activities, signage and curriculum integration could potentially increase schools' use of the resource. Strategies should be developed to reduce the barriers for using MyPlate. Future research should examine a more diverse sample of teachers and strategies to integrate MyPlate into curriculum.