The Pediatric Symptom Checklist (PSC) is a brief screening questionnaire designed to help pediatricians in busy office practice select children who are likely to have psychosocial difficulties and thus could benefit from further evaluation. We report two preliminary validation studies that indicate that PSC correlates well with the Childhood Behavior Checklist, a longer, well-validated questionnaire, and most children referred for psychiatric evaluation score above the PSC cutoff score. Developing a valid and practical psychosocial screening procedure for office practice is methodologically difficult but highly relevant to clinical practice.