Intravenous drug abusers (IVDAs) represent an increasing proportion of the HIV epidemic. Forty-three IVDA's (22 HIV-negative, 21 HIV-positive) were studied using the Mattis Dementia Rating Scale (DRS). All subjects had used intravenous heroin, but reported that they were drug-free at the time of testing. HIV-positive subjects were predominantly symptomatic and were dichotomized into AIDS and non-AIDS groups. All subjects with abnormal DRS scores were HIV-positive (57% of all HIV-positives). All HIV-negative subjects had normal DRS scores while 43% of the positive group obtained such scores. The DRS reliably identifies neuropsychological impairment, and may be a useful screening tool in this population.