The onset and time-course of HIV-associated cognitive deficits are not well established. The present experiment compared physiological and neurometric assessments of cognitive decline in HIV-asymptomatic, HIV-symptomatic, and HIV-negative control adult women. The P3 component of standard auditory, event-related electrical potentials of the brain (ERP) and standard neurometric (pencil and paper) test scores were recorded. The P3 ERP measures differentiated both of the clinical HIV groups from the control group. In contrast, the neurometric measures were more sensitive to the difference in cognitive decline between the two clinical groups. It is concluded that both P3 ERP measures and standard neurometric tests are individually useful and complementary for tracking cognitive decline in the diagnosis and treatment of opportunistic HIV-associated central nervous system impairments.