Nonhuman primates have been used as animal models in which to study cognitive changes associated with aging and age-related disease for decades. There are many advantages to using nonhuman primates for studies of aging including the capability to examine visual nonspatial cognitive processes and the ability to use operationally similar behavioral tasks to what is used with humans. Because some aspects of aging in humans do not develop naturally in nonhuman primates or do not follow the same course of natural development in monkeys, experimental models are necessary for some investigations. Research in our laboratory has identified similarities in the cognitive profiles of nonhuman primate models of aging, Alzheimer's Disease, and menopause with their human counterparts. In addition, through the use of a variety of different techniques we have used these nonhuman primate models to begin to determine the neural substrates of age-related cognitive dysfunction noted with advanced age and age-related disease. In this paper, we review our observations made in nonhuman primate models of aging, Alzheimer's Disease, and menopause and indicate areas for future research.