The Division of Lung Diseases of the National Heart, Lung, and Blood Institute (NHLBI) held a workshop to develop recommendations on topics, methodologies, and resources for comparative effectiveness research (CER) that will guide clinical decision making about available treatment options for lung diseases and sleep disorders. A multidisciplinary group of experts with experience in efficacy, effectiveness, implementation, and economic research identified (a) what types of studies the domain of CER in lung diseases and sleep disorders should include, (b) the criteria and process for setting priorities, and (c) current resources for and barriers to CER in lung diseases. Key recommendations were to (1) increase efforts to engage stakeholders in developing CER questions and study designs; (2) invest in further development of databases and other infrastructure, including efficient methods for data sharing; (3) make full use of a broad range of study designs; (4) increase the appropriate use of observational designs and the support of methodologic research; (5) ensure that committees that review CER grant applications include persons with appropriate perspective and expertise; and (6) further develop the workforce for CER by supporting training opportunities that focus on the methodologic and practical skills needed.