This outcome study compared six- and 12-month return-to-custody data for 171 treatment participants and 145 nontreated general population inmates at the Central California Women's Facility (implementing a traditional TC program). Findings showed that there were no differences between the TC treatment group and the no treatment comparison group with regard to six- and 12-month return-to-custody rates (six-month: 16% vs. 16% and 12-month: 36% vs. 27%). The only significant difference in six-month return-to-custody rates was found between treatment-only participants (21%) and the treatment plus aftercare participants (6%). Treatment participants who participated in community-based aftercare were significantly less likely to be returned to custody compared with those who did not participate in aftercare. Multivariate analysis was also used to control for the large difference in psychological impairment between the two groups and other background factors related to reincarceration, while assessing the effect of treatment group status on return-to-custody. Findings indicated that treatment/no-treatment status was not significantly related to a six- or 12-month return-to-custody. However, success on parole was associated with participation in community-based aftercare. The lack of a prison-based treatment effect could be an indication that drug-dependent women offenders need gender-responsive treatment that is designed specifically for their complex needs.