Objective: To examine predictors of opioid abstinence in buprenorphine/naloxone (Bup/Nal)-assisted psychosocial treatment for opioid-dependent youth. Method: Secondary analyses were performed of data from 152 youth (15-21 years old) randomly assigned to 12 weeks of extended Bup/Nal therapy or up to 2 weeks of Bup/Nal detoxification with weekly individual and group drug counseling. Logistic regression models were constructed to identify baseline and during-treatment predictors of opioid-positive urine (OPU) at week 12. Predictors were selected based on significance or trend toward significance (i.e., p less than 0.1), and backward stepwise selection was used, controlling for treatment group, to produce final independent predictors at p less than or equal to 0.05. Results: Youth presenting to treatment with previous 30-day injection drug use and more active medical/psychiatric problems were less likely to have a week-12 OPU. Those with early treatment opioid abstinence (i.e., weeks 1 and 2) and those who received additional nonstudy treatments during the study were less likely to have a week-12 OPU and those not completing 12 weeks of treatment were more likely to have an OPU. Conclusions: Youth with advanced illness (i.e., reporting injection drug use and additional health problems) and those receiving ancillary treatments to augment study treatment were more likely to have lower opioid use. Treatment success in the first 2 weeks and completion of 12 weeks of treatment were associated with lower rates of OPU. These findings suggest that youth with advanced illness respond well to Bup/Nal treatment and identify options for tailoring treatment for opioid-dependent youth presenting at community-based settings. (Contains 3 tables.)