According to the democratic domino theory, increases or decreases in democracy in one country spread and “infect” neighboring countries, increasing or decreasing their democracy in turn. Using spatial econometrics and panel data that cover over 130 countries between 1850 and 2000, this article empirically investigates the democratic domino theory. We find that democratic dominoes do in fact fall as the theory contends. However, these dominoes fall significantly “lighter” than the importance of this model suggests. Countries “catch” only about 11% of the increases or decreases in their average geographic neighbors’ increases or decreases in democracy. This finding has potentially important foreign policy implications. The “lightness” with which democratic dominoes fall suggests that even if foreign military intervention aimed at promoting democracy in undemocratic countries succeeds in democratizing these nations, intervention is likely to have only a small effect on democracy in their broader regions.