The Parental Concerns Questionnaire (PCQ) was designed as a parent-interview screening instrument for young children with developmental concerns at risk for potentially severe behavior problems (SBDs). Parents of 262 young children (4 to 48 months) answered to the 15 dichotomous PCQ items interviewed by trained staff. Cluster analysis for items revealed three item clusters, which we labeled Developmental/Social (8 items), Biomedical (3 items), and Behavior Problems (3 items). This paper discussed primarily the Behavior Problems cluster, with items referring to self-injurious, aggressive, and destructive behaviors. Parents' concerns about behavior problems were high, with item-endorsements of the Behavior Problems cluster ranging from 41.8 % to 68.8 %. The Behavior Problems cluster was significantly correlated with all three subscales of the Behavior Problems Inventory (BPI-01), with select subscales of the Aberrant Behavior Checklist (ABC), and with the Repetitive Behavior Scale-Revised (RBS-R) providing some evidence for concurrent validity. Sensitivity and specificity data were computed for the three PCQ items as well as for the cluster score in comparison with the BPI-01, ABC, and RBS-R showing strong sensitivity. The PCQ Behavior Problems cluster is a useful screening checklist with high sensitivity for potential SBDs in young children at-risk for developmental delays. © 2013 Springer Science+Business Media New York.