Public concerns about the costs of immigration and crime are high, and sometimes overlapping. This article investigates the relationship between immigration into a metropolitan area and that area's crime rate during the 1980s. Using data from the Uniform Crime Reports and the Current Population Surveys, we find, in the cross section, that cities with high crime rates tend to have large numbers of immigrants. However, controlling for the demographic characteristics of the cities, recent immigrants appear to have no effect on crime rates. In explaining changes in a city's crime rate over time, the flow of immigrants again has no effect, whether or not we control for other city-level characteristics. In a secondary analysis of individual data from the National Longitudinal Survey of Youth (NLSY), we find that youth born abroad are statistically significantly less likely than native-born youth to be criminally active.