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. (Contains 3 tables and 2 figures.)