A 2-wave longitudinal study of personality in adolescence was conducted with data obtained at ages 12 and 17 years from approximately 60 European American and 60 second-generation Chinese American youth. At Time 1 they completed the Children's Personality Questionnaire and at Time 2 they completed the High School Personality Questionnaire and self-report measures of high school grades, depression, and self-esteem. Chinese American and European American adolescents became more similar to each other over time through developmental and acculturative processes. Adolescents of both ethnicities increased in Extraversion and Independence. Despite this general trend, the Chinese American youth continued to report lower levels of Extraversion than European American youth. Extraversion and Anxiety predicted school grades for European Americans and psychological adjustment for Chinese Americans.