For the neuropsychological impairment which takes place in HIV-1 infection, various classification systems, based on either neuropathological criteria, severity of the disorder or functional criteria, have been suggested in the literature. This study identifies the patterns of neurocognitive disorders in HIV-1 infection and investigates their stability at one-year follow-up. Two hundred and seventeen HIV-1-positive subjects in various stages of infection and 55 HIV-1-negative subjects were evaluated. Our results suggest that there is considerable diversity in the neuropsychological functioning of HIV patients but the patterns are relatively stable, functionally distinct, and differ with respect to the severity of the deficit. The overall pattern is consistent with existing neuropsychological knowledge on HIV infection. Comparison of the patterns identified in this study with other classification systems posed several problems, however, and these problems may have important implications for the theory and methodology of neuropsychological HIV research.