Forty subjects with chronic airflow obstruction were examined independently by 2 observers, and their assessment of several physical signs was recorded. Spirometry and lung volumes were measured. Most of the signs studied correlated closely with the degree of airflow obstruction as assessed by the forced expiratory volume in one second. Certain signs also correlated closely with the degree of hyperinflation, the duration of symptoms, or the age of the subject. The agreement between observes in this study was good. Although all the signs are related in one way or another to the severity of airflow obstruction, some are due to large variations in intrathoracic pressure, some to hyperinflation and some, possibly, to changes in the shape of the chest and the action of the respiratory muscles. Hence, we suggest that these signs should not be regarded as inferior to tests of pulmonary function; physical examination and spirometry should be complementary.