The literature on legal traditions focuses on the comparative macroeconomic effects of legal systems, concentrating on efficiency alone and leaving distributive issues to taxation. However, a country’s legal structure also conditions the primary distribution of income and may have a comparative advantage over taxation as a distributive instrument. We use cross-section and panel estimates to show that the level of income inequality in a country is correlated with its legal system. By several measures of inequality, common law countries are on average more unequal than civil law countries. We explain these results by the nature of the systems. The looser regulation in common law countries limits their capacity to achieve social objectives such as combating income inequality.