Morality rates for various social groups within the population of Finland were compared, using 179 919 death certificates for the period 1969-72. Morality was generally lowest in the highest social groups and highest among unskilled workers. Male mortality from coronary heart disease was also high among lower salaried employees. In the less developed area of northern Finland, female mortality from coronary heart disease and vascular lesions of the central nervous system was highest among the agricultural population. Cancer of the breast, cancer of the intestine, and suicides among women were apparently concentrated in the higher classes. Life table analysis showed that the social group differences in life expectancy at birth could be as great as 7.2 years. It is considered indispensable for a national health policy to improve on the recording of occupational data and to give regularly the occupation of the deceased when publishing mortality rates.