There are major social inequalities in health within societies. Alcohol and tobacco are major preventable causes of ill health. Using data from the United Kingdom, this paper examines the social distribution of tobacco and alcohol consumption; the role that tobacco and alcohol may play in mediating or modifying social inequalities in health; and the implications of social distribution for policies to reduce harm associated with consumption of alcohol and tobacco. In the United Kingdom, as in many other countries, there is clear inverse association between socio-economic position and consumption of cigarettes. Over the past three decades, the decline in smoking has been more rapid in men and women in higher socio-economic groups. United Kingdom suggest that among employed men and women, the prevalence of non-drinking shows an inverse association with occupational status; heavy drinking differs little; and moderate drinking is more common among those of higher socio-economic status. Smoking accounts for perhaps 25% of the social class difference in coronary heart disease (CHD) mortality, more for lung cancer, less for some other diseases. healthier patterns of drinking may contribute to the lower CHD rates of higher social classes. Although other factors are clearly important in generating social inequalities, it is important to take the social distribution of alcohol and tobacco into account when formulating policy. For cigarette consumption, there is evidence that in lower socio-economic groups demand is more sensitive to price; higher socio-economic groups are more responsive to health education. There has been less research of this nature for alcohol. Available analyses suggest that price responsiveness of heavy drinking may be greatest in young men and in those with lower incomes. A pricing strategy has important equity implications.