This study used the Addiction Severity Index (ASI) to identify the various problems substance abuse clients present when seeking treatment at a Department of Veterans Affairs Medical Center. The sample was 98% male and 73% African-American, with a mean age of 37 years. Cluster analysis was used to identify commonalities and divergences in self-reported employment, legal, family, substance abuse, psychological, and medical problems. Four distinct clusters emerged, each of which could be characterized by a dysfunctional pattern. The utility of this approach in designing treatment regimens, addressing client problems in addition to their substance abuse, increasing client satisfaction with service provided, and decreasing treatment attrition is discussed.