Purpose/Objectives: The purpose of this project was to identify and confirm best practices for increasing high school student participation and satisfaction in school nutrition (SN) programs operating under the regulations of the National School Lunch Program (NSLP). Methods: Using a modified best practices research model (BPRM; Mold & Gregory, 2003), we developed best practice statements framed around four practice areas which were based on previous research findings and pertinent foodservice, SN, and marketing literature. Eight SN professionals participated in an expert panel work group session to review each best practice statement, classify statements under the appropriate research-based practice area, and group similar statements into goals. Using a guided evaluation, expert panel members reviewed the results of the work group session and confirmed the list of best practice statements. We drafted a best practice guide, which a review panel (N = 11) of SN directors evaluated for appropriate grouping of best practice statements into goals and practice areas, ease of use of assessment scales, formatting, and general content validity. Results: The "NFSMI Best Practice Guide for Increasing High School Student Participation and Satisfaction in the National School Lunch Program" contains 75 best practice statements grouped into 13 goals that support four practice areas (Food Quality, Staff, Program Reliability, and Marketing and Communications). There are two components to the guide: Baseline Assessment and Progress Review. The former assists the SN director in identifying best practices applicable to his/her program, as well as strategies that can be included in a plan of action for improvement, while the latter measures how effectively the plan of action is implemented. Applications to Child Nutrition Professionals: This guide provides SN professionals a research-based tool to focus improvement efforts on best practices that will have the most impact on high school students' participation in the NSLP and satisfaction with their school lunch experience. (Contains 3 tables and 1 figure.)