The growth of the private corrections industry has elicited interest in the comparative performance of state and private prisons. One way to measure the service quality of private prisons is to examine inmates' postrelease performance. Current empirical evidence is limited to four studies, all conducted in Florida. This analysis replicates and adds to the Florida measures in a different state and enhances previous methods. It uses data for a large cohort of Oklahoma state prison inmates released between 1997 and 2001. Controlling for known covariates, multivariate survival analysis revealed comparative rates of reincarceration for inmates in multiple exposure and comparison groups. These results are unique among prior studies on this topic; private prison inmates had a greater hazard of recidivism in all eight models tested, six of which were statistically significant. Finding no empirical support for claims of superior service from private corrections, the authors discuss policy implications and prospects for future research.