OBJECTIVES: to determine the cost effectiveness of three treatment alternatives (medication, behavioral, and combined treatment of Atomoxetine and behavioral therapy) for attention deficit hyperactivity disorder in children from payer perspective with time horizon: 12 weeks METHODS: a prospective trial based economic evaluation was conducted on children  in psychiatric out patients clinic at Abasseya Mental Hospital (AMH), Cairo ,Egypt who are 6 to 12 years of age (boys or girls), and had a clinical diagnoses of ADHD as defined in the Diagnostic and statistical Manual fourth edition (DSM_IV). Patients were classified into three groups: (Depended on psychiatric recommendation and parents preferences) medication only group (group I), behavioral therapy group (group II), and combined medication and behavioral therapy group (group III). Each treatment had both a cost and an outcome associated with it.  Cost effectiveness ratio comprising the average total cost per child per unit of outcome three months-Quality Adjusted Life Years "QALY" in each of the three groups.  RESULTS: The combined therapy was associated with  the highest cost effective ratio C/E Ratio of 7695.524 LE per QALY, medication therapy was 4381.927 LE per QALY,  While C/E Ratio of behavioral therapy was 3337.339 LE per QALY. According to base-case analysis, combined therapy resulted in greatest health benefits but at the same time it was the most expensive treatment option. Behavioral therapy was the least effective and cheapest option.  The sensitivity analyses: show that the utility values of all health states are crucial determinants of the cost-effectiveness results. CONCLUSIONS: combined therapy resulted in greatest health benefits but at the same time it was the most expensive treatment option. Behavioral therapy was the least effective and cheapest option.