Atomoxetine is the first nonstimulant medication for the treatment of attention deficit/hyperactivity disorder. It has been approved as a treatment for children and adolescents with ADHD in the United States, throughout Europe, and in other countries. The efficacy of atomoxetine has been documented in short and long- term studies. It is a generally safe and well tolerated drug. Most common adverse reactions include nausea, vomiting, fatigue, decreased appetite, abdominal pain, and somnolence. We report a case of bruxism induced by atomoxetine, which was observed in a child with ADHD.