The Personal Experience Inventory (PEI) is a recently developed self- report inventory that measures problem severity and psychosocial risk factors associated with adolescent alcohol and other drug involvement. Although previous studies have provided initial support for the psychometric properties of the PEI, this validity evidence was based on uncontrolled studies. The present study examined the concurrent validity of the PEI on a new sample using more controlled research procedures. Results indicated that the PEI Basic Problem Severity scales were significantly related to groups defined by DSM-III-R criteria for substance use disorders and by treatment referral recommendations. Also, the main PEI Problem Severity scale, the Personal Involvement scale, correctly classified a significantly greater proportion of participants into referral subgroups than would be expected given the base rates for the sample. This evidence provides additional support for the validity of the PEI as a problem severity measure of adolescent alcohol and other drug use.