Low agreement between self-reports and parent reports of the behavioral adjustment of adolescents has been widely documented in the literature. However, it has been little studied in connection with adoptees. In the current research, the magnitude of agreement between reports of adolescents' behavioral problems given by the adolescents themselves and their parents and the direction of the possible discrepancies between these reports were studied. A comparison was made between adopted and nonadopted adolescent-parent dyads. The research questions were tested on a sample of 294 adolescent-parent pairs (189 adoptees and 105 controls) from Belgium, Romania, Chile, Switzerland, Italy, and the Netherlands. Correlation analyses together with Fisher R to Z comparisons between countries and between adopted and nonadopted dyads and Repeated Measures Analyses revealed that both the magnitude of agreement and the direction of the discrepancies in internalizing and externalizing behavioral ratings between informants, that is, parents and their adolescent, did not depend on whether the adolescents were adopted or not. Compared with their parents, both adopted and control adolescents reported problems more frequently. Some variations in the magnitude of agreement were found between countries. An interaction effect between gender and informant indicated that discrepancies for internalizing behavior were higher in parent-adolescent daughter pairs than in parent-adolescent son pairs.