Highly active antiretroviral therapy is allowing increasing numbers of adults to age with HIV. The neuropsychological effects of aging with HIV are reviewed through three types of studies. First, the separate effects of HIV and aging on cognition are examined in studies that compare younger adults with HIV with neurologically normal older adults. Second, studies examine the impact of aging within samples of adults with HIV only. Third, providing the most critical evidence, are studies that assess cognition in younger and older adults with HIV relative to younger and older adults without HIV. In general research findings are inconclusive. Large individual differences among older adults with HIV as well as co-factors (APOE4 and detectable viral load) may account for inconsistent findings in the literature. A subgroup of older adults with HIV may be at greater risk for cognitive impairment, especially in attention functioning. © 2009 Springer Science+Business Media, LLC.