Several studies have demonstrated that behavioural therapy oriented interventions exert a positive influence on the clinical course of the attention-deficit hyperactivity disorder (ADHD). However, the long-term effects of the behavioral treatment in ADHD, especially those on neuronal mechanisms underlying this disorder, have been studied insufficiently. Functional MRI (Go-NoGo paradigm) was carried out in 9 children with ADHD before and 1.5 years after a response cost and token-based training. In the follow-up, patients were still characterized by a significant increase in activation in the anterior cingulate and in the precentral gyrus compared with recordings done before the training. It seems likely that the behavioural training elicits stable neuronal changes in children with ADHD which correspond with an improvement of neuropsychological functioning and clinical symptoms.