This article endeavors to illustrate the realities of prison life for sex offenders and the means by which they attempt to establish viable identities and acquire a survivable niche in the prison general population, particularly when established identities and protective niches are put at risk by entry into a sex offender treatment program. Qualitative data was collected by repeatedly interviewing a cohort of sex offenders for 6 months as they completed a basic sex offender treatment program. The findings indicate a need to include consideration of treatment context in understanding the limits of treatment gain in prison-based programs.