Parents' reports and adolescents' self-reports of problem behaviors in 883 11-19-year-olds from the general population were compared. Correlations between both informants' CBCL syndrome scores ranged from 0.27 to 0.56. Adolescents reported many more problems than their parents did about them. Discrepancies were larger for externalizing than for internalizing problems, were larger for girls than for boys and increased with age. The findings indicated that adolescents, especially as they grow older, are indispensable informants on their own problem behaviors.