Child Behavior Checklists completed by parents of 1863 clinically referred American and Dutch boys aged 6-11 and 12-16 were subjected to principal components analyses with varimax rotations. For each age group, the construct validity of seven empirically derived syndromes was supported by cross-national correlations ranging from 0.80 to 0.98. These syndromes were designated as Aggressive, Delinquent, Depressed (ages 6-11 only), Hyperactive, Schizoid (ages 12-16 only), Somatic Complaints, Uncommunicative, and Withdrawal (Social Withdrawal for ages 6-11; Hostile Withdrawal for ages 12-16). Cross-national similarities in the distribution of scores for normative samples supported the use of the same syndrome scales by clinicians and researchers in the two countries. The cross-national construct validity of Obsessive-Compulsive and Immature syndromes did not receive adequate support.