OBJECTIVES: This study was designed to investigate the usability of IVA + Plus (Continuous Performance Test) and NeuroGuide [Quantitative electroencephalography (EEG) normative database] as an auxiliary diagnostic tools for attention-deficit hyperactivity disorder (ADHD). METHODS: The scores of IVA + Plus and resting EEG were obtained from 34 elementary school-aged children. Also, the Korean ADHD Rating Scale (K-ARS) and the Diagnostic Interview Schedule for Children version IV (DISC-IV) was done for the parent of them. From the result of the DISC-IV, we divided them into three groups, ADHD Not Otherwise Specified (NOS), and Normal Control (NC). Using NeuroGuide, the z-scores of relative power for delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), and beta (12-25 Hz) were calculated. Then the correlation and variance analysis were done to investigate the differences between three groups. RESULTS: The scores of IVA + Plus were negatively correlated with the K-ARS. IVA + Plus have successfully discriminated the ADHD from NC and NOS. The z-scores of relative power of delta and theta were positively correlated with the K-ARS. The z-scores of relative power of alpha and beta were negatively correlated with the K-ARS. CONCLUSIONS: The IVA + Plus and NeuroGuide QEEG test are expected to be used as the valuable tools for diagnosing ADHD accurately.