The Addiction Severity Index (ASI) is a multidimensional interview, developed in the United States to assess the severity of problems in several areas, commonly associated with addiction. The ASI was translated into Dutch and adapted. The Dutch version of the ASI was administered among 264 subjects who were admitted to a clinical detoxification center. In this article the concept, usefulness and psychometric characteristics of the Dutch version of the ASI are discussed. Data are presented concerning the internal consistency of the ASI subscales, the relationship between the ASI problem areas, the formation of addict-subgroups on the basis of profile of problem severity and the concurrent validity of the ASI psychiatry scale. On the basis of the concept and the psychometric characteristics, the authors advocate to further implementation of the ASI in Dutch addiction treatment.