Cognitive impairment in schizophrenia is a major feature of the illness. Like many of the other aspects of the illness, however, it has not been studied extensively in older patients. Several studies of older patients with a lifetime course of poor outcome and chronic institutional stay have indicated that some patients manifest evidence of profound cognitive impairments on a cross-sectional basis and cognitive and functional decline over longitudinal follow-ups of 30 months or longer. Risk factors for this decline include lower educational attainment and more severe positive symptoms, but do not include more severe symptoms of physical illness. These impairments have been shown to be discriminable from normal age-related changes and from the changes associated with Alzheimer's Disease. In contrast, studies of patients with no history of lifetime institutional stay find no such evidence of either age-related changes in cognitive functioning or longitudinal decline in cognitive or functional status. Since there is accumulating evidence of progressive brain changes over the lifespan in patients with schizophrenia, the course of cognitive deficits in later life will remain an important topic, both for understanding the lifetime course of schizophrenia and for developing interventions aimed at reduction of disability in the illness.