For many decades, investigators have assessed the relationship between age and surgical outcomes. However, it is important to note that surgical outcomes of two persons of the same age may completely differ. Many have argued that frailty instead of age should be considered in surgical decision-making. Frailty is a state of reduced body reserve to withstand stress. Assessing frailty transforms a nonmodifiable factor, age, into a series of potentially modifiable factors, known as aging-related impairments. There are various interventions that can be done to improve aging-related impairments. Moreover, assessing frailty improves clinician–patient communication in discussing the risk and benefits of surgery. Whenever possible and if geriatricians and geriatric care providers are available, collaboration between geriatricians/geriatric care providers and surgeons may improve perioperative outcomes of older adults. In this section, we will introduce the concept of frailty, its assessment methods, relationship with surgical and other outcomes. We will discuss benefits of frailty assessment for the patients, their caregivers, and clinicians, and finally we will discuss some of the interventions that can be done to improve outcomes of older frail patients.