A multidisciplinary panel was convened by the American College of Chest Physicians (ACCP) to develop clinical practice guidelines for lung cancer prevention, diagnosis, and treatment. The ACCP Expert Panel on Lung Cancer Guidelines produced 20 guidelines, each related to a distinct set of management decisions. This article describes the approach used to develop the guidelines, including identifying, evaluating, and synthesizing evidence, assessing the strength of evidence pertinent to individual guidelines, and grading guideline recommendations.