Objective Validated questionnaires can improve the identification of psychosocial problems in community pediatric services. Our aim was to assess which of 3 short questionnaires - the Brief Infant-Toddler Social and Emotional Assessment (BITSEA), the Ages and Stages Questionnaires: Social-Emotional (ASQ:SE), and the KIPPPI (Brief Instrument Psychological and Pedagogical Problem Inventory) - was most suitable as a routine screening tool for identification among toddlers. Methods We included 2106 parents (response rate 81%) of children aged 6, 14, or 24 months at routine well-child visits in 18 services across the Netherlands. Child health care professionals interviewed and examined children and parents. Parents were randomized to complete either the BITSEA or the KIPPPI; all filled out the ASQ:SE and the Child Behavior Checklist. For each questionnaire, we assessed the internal consistency, validity with Child Behavior Checklist-Total Problems Score (CBCL-TPS) as a criterion, and added value to identification compared to clinical assessment alone. Results Cronbach's alphas of the total scales varied between 0.46 to 0.91. At the ages of 6 and 14 months, none of the instruments studied had adequate validity. At the age of 24 months, only the BITSEA discriminated sufficiently between children with and without problems (sensitivity = 0.84 at specificity = 0.90), but not the other 2 questionnaires (with sensitivity indices varying between 0.53 and 0.60 at similar specificity). The BITSEA at this age offered slightly higher added value to the identification of psychosocial problems by child health care professionals. Conclusions For toddlers aged 6 and 14 months, no questionnaire is sufficiently valid to support the identification of psychosocial problems. The BITSEA is the best short tool for the early detection of psychosocial problems in 2-year-old children. Copyright © 2013 by Academic Pediatric Association.