An evaluation of the effects of HIV infection on neurocognition over time is important for understanding disease progression. Changes in cognitive function can be evaluated longitudinally by using neuropsychological testing at repeated intervals. The assessment of change over time, however, is complicated by the potentially confounding influence of learning on repeated test administrations, often referred to as practice effect. In this study, we present data on testing of persons with or without HIV infection on a battery administered at study baseline and repeated 1 year later. Results suggest that practice effects may be diminished in persons with HIV infection compared to without it. This appears to be true even among those with relatively intact immune functioning as measured by CD4 count.