Human immunodeficiency virus (HIV) dementia remains as an important cause of neurological morbidity among HIV-seropositive (HIV+) individuals. Differences in the neuropsychological profiles between older and younger HIV+ individuals have not been examined extensively. The objective of this study was to examine the neuropsychological test performance between old and young HIV+ individuals (a) with and without cognitive impairment (total cohort) and (b) with dementia. One hundred thirty-three older (age >or= 50 years) HIV+ individuals and 121 younger (age 20 to 39 years) HIV+ individuals were evaluated with a standardized neuropsychological test battery. Differences between age groups in the mean z score for each neuropsychological test were determined. The older HIV+ (total) cohort had greater impairment in tests of verbal memory (P = .006), visual memory (P < .002), verbal fluency (P = .001), and psychomotor speed (P < .001) compared to the young HIV+ (total) cohort. After adjusting for differences in education, older HIV+ patients with dementia (n = 31) had a greater deficit in the Trail Making test Part B (P = 0.02) compared to younger HIV+ patients with dementia (n = 15). Age was associated with lower performance in tests of memory, executive functioning, and motor performance in older HIV+ individuals with and without cognitive impairment (total cohort), compared to younger HIV+ individuals. Among HIV+ patients with dementia, age may be associated with greater impairment in a test of executive functioning. These differences could be a result of advanced age itself or age-associated comorbidities such as coexisting cerebrovascular or neurodegenerative disease.