Life expectancy has only recently extended into old age. In many countries, declining proportions of working‐age people have to ensure adequate living conditions for a growing number of old people. To meet this challenge, societies need knowledge about positive or “successful” aging and conditions that foster them. In this chapter, we review the state of research on this topic. Early approaches focused on the question “
what
is successful aging?” by outlining general criteria for aging well. More recent approaches have shifted the focus to the question “
how
do people age successfully?” These models—e.g., the model of selection, optimization, and compensation (Baltes & Baltes, 1990), the model of assimilative and accommodative coping (Brandtstädter & Renner, 1990), or the model of primary and secondary control (e.g., Heckhausen & Schulz, 1995)—emphasize the role of proactive processes and motivational processes in shaping and adapting to age‐related changes. By adapting goals and standards to the changing availability of resources (e.g., health‐related decline), for example, older people can maintain a high level of functioning and well‐being. Hopefully, the identification of processes underlying successful aging will help to enhance the quality of older person's lives in the future.