Male employees of 2 East Coast telephone companies who participated in standardized respiratory surveys from 1961 to 1969 were followed to ascertain days of disability resulting from respiratory illnesses that lasted for more than a week. Subjects for this study were 1,386 white males between the ages of 40 and 65 yr who had had no disabling chest illnesses in the 3-yr period prior to examination. Several survey findings were predictive of subsequent days lost from work. Listed in order of importance, these were diminished forced expiratory volume, a history of ever having had asthma, marked shortness of breath, chronic cough and phlegm, and chronic wheeze. A history of ever having had hay fever was associated with a diminished risk of lost time because of respiratory illness.