Behavior problems reported by parents on the Child Behavior Checklist (Achenbach & Rescorla, 2001) were studied in 316 children adopted from social-emotionally depriving Russian institutions as a function of age at adoption (18-month cutoff), age at assessment (6–11 and 12–18 years), and gender. Children adopted after 18 months had higher problem scores predominately when assessed at 12–18 years. Although most children had no behavior problems, 59.0% of later adoptees assessed in adolescence had at least 1 subscale score and 48.7% had 2 or more subscale scores in the clinical/borderline range. A factor analysis of items that significantly related to age at adoption for older children revealed 1 broad factor, encompassing different antisocial behaviors, social difficulties, and withdrawal. These results may suggest a somewhat broader deficiency produced by orphanage experience beyond the first 18 months of life that underlies a range of behavioral problems displayed later.