This chapter provides a comprehensive overview of the role of CT angiography (CTA) in evaluating acute limb ischemia (ALI), a critical medical emergency requiring prompt diagnosis and intervention. It covers relevant vascular anatomy, including common variants, and discusses the etiology and clinical assessment of ALI. The chapter details CTA technique, including protocol considerations, potential pitfalls, and recent advancements such as dual-energy CT and dynamic CTA. It extensively explores CT findings and interpretation in emergent peripheral vascular conditions, focusing on arterial embolism, arterial thrombosis, and popliteal artery aneurysms. The importance of structured reporting in lower extremity CTA is emphasized, providing a template that facilitates accurate diagnosis and guides appropriate management decisions. By integrating clinical information with detailed imaging findings, this chapter equips radiologists and clinicians with the necessary tools to effectively diagnose and manage patients presenting with painful and cold limbs.