While the role of cultural norms in determining corruption is well-explored in the empirical literature, the relationship between a specific aspect of culture, that is, individualism versus collectivism, and corruption is rather unexplored. This paper investigates the relationship between individualism/collectivism and corruption in a large cross-section of countries. To establish causality, the paper uses an index of historical prevalence of infectious diseases and a measure of genetic distance between the population in a country from that in the United States to instrument the individualism/collectivism variable. We find that more individualistic countries have lower levels of corruption (perception). This relationship is robust to the inclusion of a rich set of control variables and to the use of alternative measures of corruption.