The frequencies of several factors, including major physical disease, in employed and unemployed men enrolled in the British Regional Heart Study (BRHS) have been compared. The BRHS is a prospective study of cardiovascular disease in middle-aged men selected at random from general practices in twenty-four towns. The unemployed group was subdivided into those who said they were unemployed because of ill-health and those who regarded their unemployment as not due to illness. The ill unemployed reported a much higher rate of doctor-diagnosed illnesses than the not-ill unemployed or the employed. The frequencies of bronchitis, obstructive lung disease, and ischaemic heart disease were higher in the unemployed than the employed, with the highest rates in the ill unemployed. The frequency of hypertension was the same in employed and unemployed men. Cigarette smoking and heavy drinking were apparently more common among the unemployed, but after adjustment for social class and town of residence only smoking was slightly higher among the unemployed. Use of tranquillisers was three to four times more common in the ill unemployed than in the not-ill unemployed or the employed. In this study, the unemployed had far more chronic physical illnesses than the employed, whether or not the employed men regarded themselves as ill. Studies of the health consequences of unemployment must allow for the pre-existing state of health, and evidence on the state of health cannot rely solely on self-reporting of illness.