The Eastern Association for the Surgery of Trauma (EAST) is a leader in evidence-based medicine and the development of practice management guidelines (PMGs) in trauma and acute care surgery. The previous primer describing EAST's approach for assessing the quality of available evidence and making recommendations for developing PMGs was published in 2000. Since that time, many new systems have been developed in an attempt to overcome previous shortcomings and to devise a methodologically rigorous and transparent approach to the assessment of quality of evidence and development of guidelines. One of these is the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. The membership of EAST has determined that the GRADE methodology will be the system used in all future EAST PMGs. The purpose of this article was thus to describe the GRADE methodology.