The incidence of cancer increases with age. Oncologists need to be adept at assessing physiologic and functional capacity in older patients in order to provide safe and efficacious cancer treatment. Assessment of underlying health status is especially important for older patients with advanced cancer, for whom the benefits of treatment may be low and the toxicity of treatment high. The comprehensive geriatric assessment (CGA) is the criterion standard for evaluation of the older patient. The combined data from the CGA can be used to stratify patients into categories to better predict risk for chemotherapy toxicity as well as overall outcomes. The CGA can also be used to identify and follow-up on possible functional consequences from treatment. A variety of screening tools might be useful in the oncology practice setting to identify patients who may benefit from further testing and intervention. In this chapter, we discuss how the principles of geriatrics can help improve the clinical care of older adults with advanced cancer. Specifically, we discuss assessing tolerance for treatment, options for chemotherapy scheduling and dosing for older patients with advanced cancer, and management of under-recognized symptoms in older patients with cancer.