Although guidance from the National Institute for Clinical Excellence recommends the improved identification of children with ADHD, clinical resources are limited. Amongst children (n = 119) referred over the question of ADHD, we evaluated the utility of screening (using parent and teacher questionnaires) prior to offering an ADHD assessment. The introduction of screening contributed to an increase in the proportion of assessed children receiving a clinical diagnosis of ADHD. Although screening of referred children prior to assessment can optimise the use of specialist clinical resources in the identification of children with ADHD, false positives remain common.