The aging of assets is inevitable, even if proper aging management techniques are utilized. Over the past few decades, many assets around the world have exceeded their designed lifetime. This chapter provides a state-of-the-art review of the management of aging assets and discusses the challenges and opportunities. First, it introduces the basic concept of aging, its definition, and causes. Second, it provides industry examples in practice. Third, it discusses knowledge development in the context of reliability, availability, maintainability, and safety (RAMS) and prognostics and health management (PHM). Fourth, it states the current research problems and makes some suggestions. Finally, it proposes a new general framework for the management of aging assets.