The concept of frailty, now being adopted in most medical disciplines, is attracting growing interest in neurology. Every day, most neurologists care for patients with varying degrees of frailty, from very mild to very severe. Frailty exacerbates patients’ health needs, complicates clinical decision making, and negatively affects their health outcomes. Increasing evidence suggests that frailty affects the risk, clinical presentation, and course of common age-related neurological disorders, including dementia, Parkinson’s disease, stroke, and multiple sclerosis.