Sexual assault is a problem in the United States of serious social concern. According to the Center for Sex Offender Management, the likelihood for incarceration for sex offenders, in addition to the length of time served in prison has increased in recent years. In an attempt to address problematic sex offending behavior, a variety of treatment programs have been implemented. The current literature has not widely examined correctional sex offender treatment programs, including the treatment experience. Regardless, policy has continued to support specialize treatment for sex offenders, highlighting the opportunity to effectively examine factors that affect treatment completion, effectiveness, and outcome in a working prison-based sex offender treatment program. Although few studies have been conducted to examine the specific characteristics associated with treatment completion in prison-based programs, treatment completion has been identified in the literature as an important contributor to sexual and general recidivism in sex offenders. Following this general overview of sex offenders, a study was conducted taking advantage of the opportunity to enhance the sex offender treatment literature. It examined variables pertinent to treatment admission, effectiveness, and completion in the Inpatient Sex Offender Program (ISOP) based in a Nebraska correctional institution. Significant results were obtained that suggest important changes in the sex offender population that influence the pool of volunteers for treatment and might impact the administration of sex offender treatment in the future. Conclusions also suggest that specific aspects of the treatment experience influence whether an offender completes or does not complete treatment. Future research into the issues pertaining to staff turnover were recommended to enhance the effectiveness of correctional sex offender treatment programs and assist in retention of both participants and treatment providers. Appendixes A-D and references