Attention Deficit Hyperactivity Disorder (ADHD) is a genetically based neurobiological disorder of children/adolescents, characterised by hyperactivity, impulsivity and difficulties in sustaining attention. Treatment of ADHD includes pharmacological interventions, counseling and parent training (multimodal treatment). In 2007 the Italian drug regulatory agency (AIFA) admitted two drugs for treatment of ADHD, i.e. methylphenidate, a stimulant that has been prescribed for a long time in the USA, and atomoxetine, a new non-stimulant drug, whose clinical effects will be reported in a national register. To estimate and compare treatment costs and quality of life over 12 months in the perspective of the Italian National Health Service. A review of published articles was performed in order to obtain data on effectiveness and QALYs gained for the two drugs. According to literature, effectiveness is defined as a post-treatment children’s response rate, measured as a >40% reduction on the ADHD Rating Scale. QALYs gained by the two drugs have been elicited from an English survey. Children with anxiety disorders, not treatable with methylphenidate, were included in the analysis. The model considers the differential response rates of the two drugs and the alternative treatment options, either for non-responders (switch to the second drug or no medication) and for patients with anxiety problems (use of atomoxetine, no medication). Only cost of drugs are included, the other psychological services being supposed equal for both treatment groups. From the meta-analysis response rates of 58.5% for atomoxetine and 66.6% for methylphenidate (44.9% after excluding children with anxiety disorders) were calculated. The average QALY associated with atomoxetine was 0.948 and with methylphenidate 0.915. In the base hypothesis the incremental cost per QALY for atomoxetine was €24,231, while in the no medication hypothesis €19,226. The sensitivity analysis showed a range of incremental costs per QALY between €18,122 and €25,427. The incremental cost utility ratios resulting from this study are consistent with other studies and are well below the threshold commonly accepted at international level, reflecting the willingness to pay of a public health service.