For 1,615 children and adolescents aged 14 to 16 years from the general population, parents completed the Child Behavior Checklist (CBCL) at initial assessment. At follow-up 14 years later, subjects completed the Young Adult Self-Report (YASR) and their parents completed the Young Adult Behavior Checklist (YABCL). Of subjects who were initially classified as deviant, 14 years later 41 percent were classified as deviant according to their YABCL Total Problem score and 29 percent according to their YASR Total Problem score. Intrainformant (CBCL/YABCL) Withdrawn, Social Problems, Delinquent Behavior and Aggressive Behavior scores, and cross-informant (CBCL/YASR) Anxious/Depressed, Thought Problems and Delinquent Behavior scores were independent predictors of general levels of problem behavior. Childhood and adolescent problems persisted to a considerable degree into adulthood, although the majority of children who were deviant at initial assessment could not be regarded as deviant 14 years later. Children who were adolescents (12-16 years) at initial assessment showed higher stability of problem behaviors than subjects who were children (4-11 years) at initial assessment. Tables, references