Science and agriculture professional organizations have argued for agricultural literacy as a goal for K-12 public education. Due to the complexity of our modern agri-food system, with social, economic, and environmental concerns embedded, an agriculturally literate society is needed for informed decision making, democratic participation, and system reform. While grade-span specific benchmarks for gauging agri-food system literacy have been developed, little attention has been paid to existing ideas individuals hold about the agri-food system, how these existing ideas relate to benchmarks, how experience shapes such ideas, or how ideas change overtime. Developing a body of knowledge on students' agri-food system understandings as they develop across K-12 grades can ground efforts seeking to promote a learning progression toward agricultural literacy. This study compares existing perceptions held by 18 upper elementary students from a large urban center in California to agri-food system literacy benchmarks and examines the perceptions against student background and experiences. Data were collected via semi-structured interviews and analyzed using the constant comparative method. Constructivist theoretical perspectives framed the study. No student had ever grown their own food, raised a plant, or cared for an animal. Participation in school fieldtrips to farms or visits to a relative‘s garden were agricultural experiences most frequently mentioned. Students were able to identify common food items, but could not elaborate on their origins, especially those that were highly processed. Students' understanding of post-production activities (i.e. food processing, manufacturing, or food marketing) was not apparent. Students' understanding of farms reflected a 1900's subsistence farming operation commonly found in a literature written for the primary grades. Students were unaware that plants and animals were selected for production based on desired genetic traits. Obtaining food from areas with favorable growing conditions and supporting technology (such as transportation and refrigeration) was an understanding lacking in the group. Furthermore, most spoilage prevention technologies employed today were not an expressed part of student's schema. Students‘ backgrounds and experiences did not appear to support the development of a robust agri-food system schema. An agricultural science and technology schema appears poorly developed in each of the students.