The British Registrar General's Social Classification has been strongly criticised for its lack of explanatory value. Furthermore, studies of social inequality in coronary heart disease (CHD) outcomes have often found associations between measures of inequality and heart disease unaccounted by conventional CHD risk factors. Alternative occupational classifications such as the Erikson-Goldthorpe schema and the Cambridge scale could be used to explore potential causal narratives which explain such residual associations. Results from a longitudinal study of adults in Britain show that the Cambridge scale has the strongest association with CHD and part of its strength is due to its strong association with CHD related health behaviours. Women classified by their partner's occupation had stronger associations with CHD compared to classifications by their own occupation. Job strain may not account for the observed social inequalities in CHD. The Cambridge scale shows stronger patterns of linear association with CHD than the RGSC and should be included in other studies of social inequality in health in the U.K.