A relatively high prevalence of neuropsychological impairment has been reported among individuals within the spectrum of HIV-1 disease. These deficits range from mild motoric slowness to a severe dementia characterized by forgetfulness, psychomotor slowing, impaired performance on "frontal systems" tasks, and frequently, dysphoric affect. This paper reviews the preliminary evidence to date on the prevalence and pattern of neuropsychological deficits within the spectrum of HIV-1 infection. Common methodologic pitfalls in this research arena are reviewed. Finally, implications for clinical practice are discussed, with emphasis on construction of screening and more comprehensive neuropsychological test batteries specifically for this population.