This article reviews the significant effects of aging on cognitive function. As people age, brain tissue volume decreases, white matter hyperintensities increase, and associated deficits are seen in working memory, attention, and executive function. Comorbidities include hypertension, diabetes, and cardiovascular risk factors. Another factor that affects cognitive function is the presence of apolipoprotein E-4, which is negatively correlated with cognitive function. In addition, decreased serum levels of endogenous sex hormones are related to changes in cognitive function, but hormone replacement therapy may be detrimental. Improved cognition has been associated with moderate alcohol intake, regular exercise, and exposure to novel stimuli. This article also examines research evaluating brain-plasticity-based training and rehabilitation to reverse losses in sensory, cognitive, and motor processing. Rehabilitation nursing strategies for dealing with the decline of cognitive function include educating patients and developing a program about lifestyle changes that will enhance cognitive stimulation; minimizing risks for and effects of hypertension, diabetes, and cardiovascular disease; recognizing and accommodating sensory deficits; and maintaining awareness of current research outcomes to guide evidence-based practice.