Age-adjusted standardized mortality ratios (SMRs) and life tables in male occupational groups for all causes and major diseases such as malignant neoplasm of stomach and lung, cerebrovascular disease, ischemic heart disease, traffic accidents and suicide was compared between Japan and Great Britain. Except for traffic accidents and suicide, males in higher employment grades had lower SMRs which had also been found to be related to other social class indicators such as perinatal death rate, the frequency of work absence and current smoker's rate. Occupational differences in mortality rates for major diseases became smaller with advancing age in Great Britain but not necessarily in Japan. The present authors concluded that inequalities in socio-economical factors were more likely to be the primary factors for survival, and that selection such as occupation and occupation-related lifestyle might still be an important factor for the inequalities. These inequalities were more obvious in Japan, where a life expectancy was, however, best in the world.