Since the operational definition of "cognitive frailty" was proposed in 2013 by the International Academy of Nutrition and Aging and the International Association of Gerontology and Geriatrics, several studies have shown the prevalence and outcomes of cognitive frailty. The prevalence of cognitive frailty is quite low in the community settings when the original definition is applied, but higher in clinical settings. In longitudinal studies, cognitive frailty is a risk for disability, poor quality of life, dementia, and death. For cognitive frailty, multimodal interventions would be effective to reduce the risk of adverse health outcomes in older people.