Objectives: Opioid detoxification with subsequent naltrexone is found to be an effective method as the first step in an abstinence-oriented approach. The aim of this study is to investigate the predictive value of variables for abstinence in opioid-dependent patients. Methods: Opioid-dependent patients were followed up to 1 month after detoxification. Predictor variables were assessed at baseline, during detoxification, and at discharge. Primary outcome was abstinence assessed by analyzing urine samples and self-reports. Logistic regression was used to identify predictors of abstinence. Results: Of 272 participants, 211 could be rated as abstinent (59.2%) or nonabstinent (40.8%) at 1 month follow-up. Significant baseline predictors were severity score of justice/police (ASI) and physical quality of life (SF-36); discharge predictors were general quality of health (SF-36) and sleeping problems (SCL-90); change in sleeping problems (SCL-90) during detoxification was also a predictor. The explained variance of these predictors was very low and clinical significance was limited. Conclusions: Considering the results it seems not possible to predict who will be abstinent or not 1 month after detoxification. Because rapid detoxification is found to be an effective detoxification method in selected patients, it seems warranted to recommend that patients with similar characteristics (ie, patients motivated for an abstinence-based treatment and low non-drug-related severity scores on the ASI) should be regarded as eligible for rapid detoxification.