Objective: The objectives of the current study were to ascertain feasibility and acceptability of directly delivering a cognitive-behavioral therapy (CBT) group intervention for inattentive children in a school setting, to examine the reliability of the RATE-C Questionnaires that accompany the program, and to determine whether they can be used to measure outcome. Method: Eighty-eight parents/carers, their children (age 8-11), and teachers at mainstream primary schools in London participated by completing the RATE-C Questionnaires; 48 participated in the group treatment following which the Questionnaires were readministered together with a semistructured interview. Results: The intervention had a completion rate of 92%. Postgroup interviews supported the acceptability of a direct intervention with young children. Reliability of the RATE-C Total scores was excellent for parent/carer, child, and teacher ratings; post-intervention parent/carer ratings indicated significant improvement on scales of attention, emotion, and conduct with medium to large effect. Conclusion: The results support the reliability of the RATE-C Scales, and feasibility and acceptability of the RAPID intervention. (Contains 3 tables.)