Sleep-disordered breathing (SDB) and attention deficit hyperactivity disorder (ADHD) are common disorders diagnosed in children. Although these diagnoses were previously considered unrelated, research now is showing that some symptoms of ADHD, specifically oppositional behavior, hyperactivity, and impulsivity, can be related to SDB in children and differs from bona fide ADHD. This article explores the connection between the two disorders and the importance of identifying and screening for SDB in children presenting with similar symptoms related to ADHD. The article also examines symptom improvement in patients with ADHD symptoms after an adenotonsillectomy, one of the first-line treatments for children diagnosed with SDB; this procedure may reduce the need for long-term stimulant use in some children with ADHD.