The study aimed to find out which differences and similarities emerge in the self-concepts of early and late adolescents and young, middle-aged, and older adults. A total of 822 participants, including 530 adolescents aged 9-19 (over 50% were girls) and 292 adults aged 20-71 (over 80% were women), from Estonia provided their spontaneous self-descriptions. Early adolescents described their preferences, appearance, family, peers, and peripheral attributes more frequently and traits, identity, and global attributes less frequently than other age groups. Late adolescents' self-descriptions included significantly more traits and fewer social roles, identity, and family mentions than those of adults. The three adult groups were similar in the use of different attributes to describe themselves. Overall, the study suggests that early adolescents describe themselves mainly through concrete, objective attributes, late adolescents through abstract psychological attributes, and adults through social-psychological attributes.