This study assessed both prevalence rates of substance dependence and level of treatment need among recently-incarcerated prisoners in a southeastern state. Participants were 752 consecutive admissions to the state prison system in 2002. They were administered the 93-item Substance Abuse Subtle Screening Inventory (SASSI). The results indicated that approximately 72% of participants met criteria for substance dependence and 46% of participants met criteria for prison-based residential treatment. The results of this study can be used to inform allocation of prison-based treatment resources.