Superoxide dismutase (SOD) is an antioxidant enzyme that scavenges superoxide radicals, and are found in all living cells. SODs have been studied as a therapeutic tool for very diverse pathological situations for more than 30 years and, in many animal models and a few clinical trials, their use has shown positive outcomes. In this book, Chapter One begins with an overview of the association between manganese superoxide dismutase and cardiovascular disease. Chapter Two examines the indispensable roles of superoxide dismutation in mammalian erythrocytes. Chapter Three discusses the structure, catalysis and therapeutic uses of the Fe/Mn SOD family. Chapter Four reviews several strategies of nanomedicines development that have been used to prolong the circulation time and improve the therapeutic action of SODs. Chapter Five studies the emerging role of SOD3 in controlling skin inflammation and immune responses.