New treatment strategies to attention deficit hyperactivity disorder (ADHD) have been introduced recently. We report and review the effect of oral ferrous sulfate administration in a 14 year old girl with ADHD, who has decreased serum iron, ferritin levels. We administered oral ferrous sulfate 120 mg to her for 8 weeks. There were improvements of scores in Attention Diagnostic System (ADS), Clinical Global Improvement (CGI), Comer's ADHD Rating scale and Dupaul ADHD Rating scale.