Aging is an extremely complex phenomenon that has many manifestations at the molecular, cellular, and whole-body levels, and in some form involves virtually all living beings. It is a process characterized by a general progressive deterioration of the physiological functions of the organism leading to increased susceptibility to diseases. This article summarizes the basic features and molecular hallmarks of aging and describes some of the genetic mechanisms of this phenomenon. It deals with the particular genes and molecular pathways involved in the regulation of aging as well as promising possibilities of interventions affecting this process.