Aim: To evaluate the validity and potential value of the parent-completed Infant/Child Monitoring Questionnaire (IMQ) as a screening measure for developmental delay in high-risk infants.Methods: One hundred and forty-one term infants born with moderate or severe newborn encephalopathy (NE) and 374 randomly selected comparison infants were administered a Griffiths Mental Development Scales (GMDS) assessment and an IMQ concurrently. Concordance of classifications between measures was compared for agreement, sensitivity, specificity, positive predictive value, negative predictive value, false positives and false negatives.Results: Overall, sensitivity and specificity of the IMQ for infants with NE averaged across all age groups was 87%, positive predictive value 57% and negative predictive value 97%. The IMQ did not perform as well for comparison infants with a sensitivity of 50%, specificity 94%, positive predictive value 15% and negative predictive value 99% averaged across all age groups. Overall under-referral for infants with NE was 13%, compared with 50% for comparison infants.Conclusions: Use of the IMQ as an accurate screening measure in infants ‘at risk’ of developmental delay is supported. The low sensitivity of the IMQ for the comparison infants indicates a need for caution when considering its application for general population screening.