ABSTRACT The term autonomy literally refers to regulation by the self. Its opposite, heteronomy, refers to controlled regulation, or regulation that occurs without self-endorsement. At a time when philosophers and economists are increasingly detailing the nature of autonomy and recognizing its social and practical significance, many psychologists are questioning the reality and import of autonomy and closely related phenomena such as will, choice, and freedom. Using the framework of self-determination theory (Ryan & Deci, 2000), we review research concerning the benefits of autonomous versus controlled regulation for goal performance, persistence, affective experience, quality of relationships, and well-being across domains and cultures. We also address some of the controversies and terminological issues surrounding the construct of autonomy, including critiques of autonomy by biological reductionists, cultural relativists, and behaviorists. We conclude that there is a universal and cross-developmental value to autonomous regulation when the construct is understood in an exacting way.