Purpose/Objectives: The purpose of this project was to develop and validate a survey that will enable school nutrition (SN) directors and managers to identify and address issues affecting the non-participation of high school students in the National School Lunch Program (NSLP). Methods: The research was conducted in two phases. Qualitative data from Phase I focus groups explored the perceptions and barriers to participation as identified by high school students and school nutrition (SN) professionals. Responses were transcribed, summarized, and classified into common themes used in Phase II survey development. A series of pilot tests were conducted to refine and validate the instrument. Factor analyses were used to statistically collapse responses into meaningful categories reflecting factors affecting non-participation. Results: Focus group discussions revealed that students who eat school lunch three or more times per week have different concerns than students who eat two or less times per week. Survey development in Phase II focused on measuring factors that affect the non-participation of students who ate two or less times per week. Factor analyses showed that low participation can be attributed to six key issues. Operationally controllable issues included food quality, staff, and access to food. Issues external to the SN program included seating capacity of facilities, food brought from home, and schoolwork. Additionally, students stated that they would be most likely to participate if they saw improvements in the following attributes: overall quality of the food, variety of menu items from day to day, and time spent waiting in line. Applications to Child Nutrition Professionals: The survey developed specifically targets students who eat in the school cafeteria two or less times a week. Results will be useful in helping SN professionals identify the specific issues that can be improved to increase participation. In addition, results will provide researchers a foundation for developing a best practice guide for addressing participation issues in the high school setting. (Contains 2 tables and 1 figure.)