This contribution aims to examine how different areas of self-regulation are related to academic achievement in adolescents and young adults. The study involved participants, drawn from following age groups: 14-15, 17-18 and 22-23. In order to get information about cognitive, metacognitive, motivational and emotional aspects of self-regulation, self-report questionnaires were used. Differences between age-groups revealed following tendency: there has been a decrease in all fields of self-regulation from age of 14 (end of primary school) to the age of about 18 years (end of secondary school), and then results slowly improved to the age of about 22 years (students of undergraduate studies). The results obtained are mirroring perceived competence of self-regulation and differ from the results concerning metacognitive accuracy. Metacognitive self-regulation persists as an important predictor of school achievement at all developmental levels, and the motivational self-regulation has significant impact on performance in the first and second age group. (Contains 5 tables.)