Emergency aortic valve replacement (AVR) is a critical intervention for life-threatening conditions for patients with haemodynamic instability, acute heart failure, or cardiogenic shock that cannot be managed medically. Emergency AVR has significantly higher risks than elective procedures due to instability of patients and limited preoperative optimisation. This chapter will explore emergency AVR in the context of three major clinical indications: infective endocarditis, critical aortic stenosis, and severe acute aortic regurgitation. It explores indications, preoperative planning, surgical techniques, and outcomes, emphasising the importance of multidisciplinary management for improving procedural success and survival of critically ill patients.