Single ventricle physiology occurs when one of the ventricles is hypoplastic or absent. Therefore, blood to the pulmonary and systemic vascular beds is pumped by one ventricle. The development of a number of operations, combined with a greater understanding of the physiologic requirements for success after single ventricle reconstruction has resulted in dramatic improvement in outcomes. This review highlights the anatomy and physiology of single-ventricle patients before, during and after surgical palliation. Besides, the anesthetic challenges presented by single-ventricle patients are also reviewed.