Calculating the cost-effectiveness of interventions is an important step in accurately assessing the health and financial burdens of a disease. Although clinical trials that include cost data can be used to compare the cost-effectiveness of specific interventions, they only deal with outcomes within the time frame of the trial. Health economic models can synthesize epidemiologic, clinical, economic, and quality-of-life data from many different sources and extrapolate results to a point many years in the future. The models generally compare interventions with respect to the costs per life-year gained or per quality-adjusted life-year gained. The use of health economic models to assess the economic burden of chronic obstructive pulmonary disease (COPD) and the value of interventions is growing, and will continue to do so as the burden of the disease is better appreciated. Several COPD disease-state models have been described; each uses a consistent definition of COPD severity that is based on FEV(1)% predicted, but the models differ in the allowed transitions, disease progression estimates, utility weights, and costs. This article reviews COPD health economic models and discusses the importance of survival benefits and utilities (health state valuations) for COPD in economic models.