Aging is a physiological and complex process associated with increasing age of living organisms. Simple model organisms have brought significant advances in our understanding of the aging process. Caenorhabditis elegans, a nematode originally used to establish the genetic and molecular basis of development, has become one of the leading model organisms for research on aging. This invertebrate has allowed identifying a connection between cellular signaling pathways and longevity. Although C. elegans is not suitable for analysis of the complete process of human aging, it remains a model of choice to analyze specific aging mechanisms and phenotypes.