OBJECTIVE Variables that have been identified as predictors of outcome of substance abuse treatment--coping style, addiction severity and addiction-related problems, psychopathology, and treatment motivation--were examined as predictors of outcome of inpatient detoxification. METHODS A cohort of 175 drug abuse patients consecutively admitted to an inpatient detoxification clinic in the Netherlands were assessed. Baseline data were obtained on psychopathology using the Symptom Checklist-90, on severity and addiction-related problems using the Addiction Severity Index (ASI), on personal coping style using the Utrecht Coping List, on motivation using the CMRS scales, and on sociodemographic background. Positive detoxification outcome was defined as transfer to inpatient rehabilitation treatment. RESULTS Of the 175 admissions, 81 (46 percent) had a positive outcome, and 94 (54 percent) had a negative outcome. Severe drug use and severe medical problems, as measured by the ASI, were the best predictors of a negative outcome of detoxification. Self-rated suitability of postdetoxification treatment was also a predictor of positive outcome, although to a lesser degree than the ASI variables. Established predictors of residential drug abuse treatment outcome, such as psychopathology, coping style, and sociodemographic variables, did not predict outcome of detoxification. CONCLUSIONS Caution is necessary when applying results of inpatient treatment outcome studies to inpatient detoxification programs. Different factors may play a role in the outcome of detoxification. To improve the rate at which patients in detoxification programs are transferred to longer-term rehabilitation, more attention should be paid to medical conditions and to the direct consequences of drug use, such as withdrawal symptoms and craving during detoxification.