Recent research has shown the relevance of the gun trafficking phenomenon from the U.S. to understand the spike of violence experienced in Mexico during the last decade. Not all American sub-national states, however, contribute in the same proportion to gun trafficking into its southern neighbor. To understand this variation, this article explores how states with high presence of gun-shows are more likely to engage in this international crime in comparison with others where these exhibitions are not as common. For this purpose, the authors ran a multivariate regression using state-level information from the U.S. The dependent variable used is the percentage of firearms that were traced back to a particular American state considering a recently disclosed sample of guns recovered in Mexico between 2006 and 2011. The independent variable is an approximation of annual gun-shows held per state. Control variables include: the flexibility of the U.S. state’s firearms regulations (expressed by Brady Index) and the distance in kilometers from the U.S. state’s capital to the closest border with Mexico. Empirical test suggests that distance to the U.S.-Mexico border and gun-shows have a significant effect on increasing the propensity of a given American state to traffic proportionally more guns into Mexico.