Frailty in older patients with cancer increases the risk of treatment related toxicity, mortality, physical decline, and quality of life. This review summarises various screening tools. Screening tools identifying frailty serve multiple purposes, providing awareness of health issues impacting oncologic treatment and prognosis and facilitating the delivery of a Comprehensive Geriatric Assessment (CGA). CGA is an overall health assessment and treatment targeting frailty. Providing CGA to older patients with cancer reduces the risk of toxicity and functional decline, increases treatment completion, and prevents loss of quality of life.