Infection with the human immunodeficiency virus (HIV-1) results not only in immunologic dysfunction but also in neurological and neuropsychological illness. Ten percent of all patients with the acquired immunodeficiency syndrome (AIDS) have a neurological complaint as their first sign of illness, 37% of AIDS patients have significant neurological dysfunction during their lifetime and 75% have neuropathological abnormalities on autopsy. Neuropsychological abnormalities have been reported in 8% to 67% of patients with AIDS and in 10% to 40% of people with HIV-1 infection. Neurological illness arises not only as a result of opportunistic processes but also as a result of primary HIV-1 infection of the nervous system. Thus, the large numbers of people infected with HIV-1 are also at risk of developing neurological or neuropsychological illness, even in the absence of immunological dysfunction or systemic illness. Since the first reports of HIV-1-related neurological illness in 1983, research into the neurological and neuropsychological complications of AIDS and HIV-1 infection has provided a number of new insights into the mechanisms and clinical manifestations of HIV-1 infection of the nervous system. The goal of Neurological and Neuropsychological Aspects of HIV Infection, an annual satellite meeting prior to the annual International Conference on AIDS, is to bring together the world's experts in various aspects of HIV infection and its neurological and neuropsychological complications. This meeting will begin with several plenary talks which will review the most important recent results of research in these areas. During the open scientific sessions which will follow, researchers from around the world will be able to share the results of their research in this field and have a forum for the discussion of this research. On a biyearly basis, the first day of this three day meeting will consist of an overview course on the neurological and neuropsychological complications of AIDS and HIV infection, presented by the world's experts in these areas. This international scientific meeting should result in an increased awareness of the neurological and neuropsychological aspects of AIDS and HIV infection; this increased awareness should result in improved care of patients with HIV infection as well as directing and coordinating future research into this critical area. Our first annual meeting in Quebec City, prior to the Vth International Conference on AIDS in Montreal, was an unqualified success with over 220 participants from around the world. With this overwhelming initial response, we plan to continue the Neurological and Neuropsychological Aspects