Although corruption poses fundamental challenges to both democratic governance and market economies, surprisingly little political science research addresses corruption in a comparative context. In this article we explain variation in the perceived level of corruption (defined as the misuse of public office for private gain) across fifty countries. We propose a set of hypotheses that explain variation in corruption levels in terms of domestic political-economic structures, democratic norms, and integration into the international economy. Levels of corruption, we propose, are higher: 1) the greater the extent of state control of the economy, 2) the weaker the democratic norms and values, and 3) the lower the degree of integration into the world economy. The multivariate data analysis broadly confirms our predictions, each of the independent variables is significant in the direction we expected.