The passage of immigration enforcement laws, traditionally the purview of the federal government, by Arizona and other states raises the concern that state and local law enforcement agencies may engage in racial profiling when enforcing immigration laws. This paper provides an overview of the issues surrounding immigration enforcement at the local level, which is a relatively new phenomenon; describes several approaches for detecting racial profiling by police; and calls for the mandatory collection of data by law enforcement agencies so that these approaches can be used to monitor the implementation of state and local immigration enforcement laws to ensure that they are applied in a race-blind manner.