Although it is widely accepted that stimulants are used as the treatment of choice in attention deficit hyperactivity disorder, many decision makers do not have appropriate information regarding an optimal first-line agent in treating this patient population. The cost effectiveness in choosing methylphenidate (Ritalin) or amphetamine/ dextroamphetamine mixed salts (Adderall) as a first-line agent in the treatment of attention deficit hyperactivity disorder is evaluated. This report uses decision-tree analysis to evaluate the cost effectiveness of basing decisions on three treatment arms: initiation with methylphenidate, initiation with amphetamine/dextroamphetamine or no treatment. Data inputs such as efficacy rates, side effects, compliance rates and school administration rates were extracted from a literature review. A societal perspective was used to estimate outcomes in terms of incremental cost and incremental utilities over the time horizon of 1 year.