The persistence of adolescents' political attitudes and behaviors into adulthood is a perennial concern in research on developmental psychology. While some authors claim that adolescents' attitudinal patterns will remain relatively stable throughout the life cycle, others argue that the answers of adolescents in political surveys have but a limited predictive value for their future attitudes and behaviors. In this article, we tackle this question on an aggregate level, by comparing survey data for 14, 18 and 18 to 30 year old respondents from eight European countries (n = resp. 22,620; 20,142 and 2800). We examine political trust, attitudes toward immigrants' rights and voting behavior. The analysis suggests that country patterns with regard to political trust and attitudes toward immigrant rights are already well established by the age of 14. We find less indications for stability in the relation between intention to vote (for 14 and 18 years olds) and actual voting behavior (for young adults). The latent structure of the political trust scale was found to be equivalent for the three age groups we investigated. We close by offering some suggestions on why attitudinal stability seems stronger than behavioral stability.