Inhibition of prepotent response is an executive function and is subserved by prefrontal cortex of the brain in healthy subjects. Damage to these regions results in response inhibition deficits. Response inhibition deficits have been linked to several neurological disorders. Some disorders like ADHD(Attention Deficit Hyperactivity Disorder) is associated with general cognitive impairments in addition to inhibitory deficits. In this study, attentional processes in ADHD have been examined using matching Stroop task and fNIRS(functional near-infrared spectroscopy).