Chronic obstructive pulmonary disease (COPD) is the result of many years of accelerated decline in lung function in susceptible cigarette smokers. Although risk factors for the susceptibility of smokers to COPD have been established, there are still large gaps in our knowledge of the biological basis for these risk factors and of how to identify individuals at risk. COPD is the fourth leading cause of death and, in contrast to other major chronic diseases in the United States, has not shown declines in mortality over the past 20 years. Mortality trends reflect patterns of initiation of cigarette smoking that occurred 30 to 50 years previously. Current mortality trends indicate that COPD mortality may be leveling off among white males, but will continue to increase among women, African-Americans, and the elderly. Recent studies indicate that early identification of individuals with airflow obstruction and smoking intervention can halt the progression of COPD, but widespread screening and intervention programs have not yet been established.