The conventional form of detoxication for illicit drug users in German psychiatric hospitals is an inpatient treatment approach connected with high admission prerequisites. These demand a high stage of motivational compliance from of the patients, e.g. the determination to continue with long-term treatment aiming at a life free of drugs. This strategy is termed "high-threshold" approach. A new form of inpatient treatment is the "low-threshold" approach offering intervals of some days or weeks free of drugs to illicit drug users, supported by professional detoxication strategies. This study compares client characteristics of illicit drug users treated at "high-threshold" vs. "low-threshold" units. A new subpopulation of clients could be reached who are more advanced in their drug intake careers and less influenced by social pressure to enter treatment. The differences in clients treated can be explained rather by differences in admission prerequisites than by a more balanced distribution of sexes in the newly introduced detoxication programme.