Recent years have seen a great increase in research on personality development; however, most research has employed self-report questionnaires and concerned individuals older than 10 years. Whereas individual differences in younger children have traditionally been studied as temperament, studies have begun to explore personality development in the first ten years of life using parent and teacher ratings. The Big Five traits of Extraversion, Neuroticism, Agreeableness, Conscientiousness and Openness have accumulated the most evidence on age changes in personality; relatively less is known about age differences in lower-order traits, and evidence on the development of the higher-order traits is lacking. In this article, I briefly describe the hierarchical structure of child and adolescent personality, summarise research on developmental trends in mean levels of personality traits across the first ten years of life and in adolescence and address gender differences in the development of traits. I conclude by highlighting some directions for future research. The scope of the present review is limited to normal personality traits in childhood and adolescence measured by widely used instruments.