Frailty is a complex age-related clinical state with a decline in physiological capacity resulting in an increased susceptibility to stressors. Frailty independently predicts both short- and long-term all-cause mortality and other disabilities in patients with peripheral arterial disease (PAD). Confirmation of frailty status facilitates risk stratification of patients with PAD. There are several types of validated assessment tools available for frailty screening to date. However, an agreed international consensus on the most practical frailty assessment tool for patients with PAD is lacking and urgently needed. This will allow harmonisation of global research data collection for better understanding of frailty and its clinical impact, therefore, ensuring a better goal-focused clinical care. This chapter describes the definitions of different types of frailty and several selected frailty assessment tools, and highlights the clinical impact of frailty among patients with PAD and its management.