Current approaches to screening for ADHD result in high rates of false positives. A proof of concept study to investigate the added benefits in the school-based detection of ADHD of adding a standardised teacher to teacher interview to traditional parent and teacher report questionnaires. A school-based study of diagnostic accuracy of ADHD using a novel 2-stage screening process. Participants were all 1026 pupils enrolled in grades 1 to 6 (ages 6-12 years) of a school in Hunan Province, China. The primary outcome was a diagnosis of ADHD on the Kiddie Schedule for Affective Disorders and Schizophrenia Present Lifetime version. 230 (22.4%) of the 1026 students screened positive at Stage 1 (parent and teacher questionnaires) (Sensitivity 0.86 [95% CI, 0.75 to 0.96], specificity 0.80 [95% CI, 0.78-0.83], false positive rate 0.20 (95% CI, 0.18 to 0.23), false negative rate was 0.14 (95% CI, 0.12 to 0.16). 65 remained screen-positive at the Stage 2 screen (teacher to teacher SNAP-IV interview). 36/65 (55.4%) of these Stage 2 screen positive participants and 1/144 (0.7%) of the screen negative subjects met DSM-IV criteria for ADHD (sensitivity 0.83 [95% CI, 0.71-0.95]; specificity of 0.97 [95% CI, 0.96-0.98]; false positive rate 0.03 [95% CI, 0.01 to 0.04], false negative rate 0.16 [95% CI, 0.15 to 0.19]. Adding teacher to teacher interviews to traditional questionnaire-based screening has the potential to improve the clinical utility of school-based screening for ADHD reducing the proportion of false positives, without a negative impact on sensitivity.