Mortality rates in Denmark and Scotland are high compared to rates of the other countries of the European Union (EU). Moreover, the evolution of mortality between 1970 and 1999 is very different between the two countries. Differences in lifestyle as possible explanations have been explored. Mortality rates from all causes, total cardiovascular, total cancer and lung cancer for both sexes and from female breast cancer were provided by WHO. Food supply data have been obtained from FAO and smoking rates from published data. Risk factor distribution has been obtained from the Monica survey. The initial mortality was high in both countries for all diseases explored, but highest in Scotland. Progressively the mortality rates between Scotland and Denmark have equalized, especially due to a more rapid decrease of mortality in Scotland. The decrease in all-cause mortality, both in Scotland, Denmark and the EU is almost exclusively due to a decrease of non-cancer mortality, especially TCV mortality. In conclusion, changes in smoking habits and in animal (saturated) fat intake, more pronounced in Scotland, offer the best explanation for the observed changes in mortality. Smoking and nutrition appear to be the most important determinants of mortality in industrialized countries.