One of the uses of the Child Behavior Checklist is as a screening instrument for childhood psychopathology in two-phase designs. The present report involves a two-phase epidemiological survey conducted in Puerto Rico in which the CBCL was used as a screening instrument during the first stage, and children were evaluated clinically during the second stage. The data indicate that in using the CBCL for screening for psychopathology in children, parent information is most informative, particularly for children in the adolescent age group. Nevertheless, the data also reinforce the need to obtain teacher information with the Teacher Report Form to enhance screening sensitivity. In this population, the data obtained with the Youth Self-Report were found to be of limited usefulness for screening purposes.