This article reports findings from the National Institute of Justice's Multi-Site Adult Drug Court Evaluation concerning the impact of drug courts on crime and incarceration. The study found that drug courts reduced the number of criminal acts by more than half over an 18-month tracking period. Published in the Journal of Experimental Criminology, Volume 8, Number 2 (2012), and available from SpringerLink online at http://www.springerlink.com/content/q555w562154l4011/.