Background: The relationship between ADHD and thyroid hormones has been controversial and widely debated. A range of thyroid abnormalities have been noted in relationship with ADHD. This study was conducted to assess thyroid hormones level in children with ADHD and compare them with healthy controls. Methods: A sample of 46 participants (23 cases, 23 controls) was taken, cases satisfied the diagnosis of ADHD according to Diagnostic and statistical manual of mental disorder (DSM-5) and fulfills the inclusion criteria, diagnosis of ADHD was confirmed by ADHDT (The AttentionDeficit/Hyperactivity Disorder Test OF James E. Gilliam). Stanford–Binet Intelligence Scales- 5th edition (SB5) was performed to assess intelligence quoitent (IQ) of the selected children. Results: There was statistically significant difference between the case and control groups regarding child abuse and being have family history. Also, there was statistically significant difference between the case and control groups regarding performance, total IQ, they were lower in cases than control. On comparing between three subtypes of ADHD, there was statistically significant difference between them regarding child abuse being 100% in hyperactive, 66.7% in combined and 0.0% in inattentive subtype. Also, total T4 was significantly lower in inattentive subtype. Conclusion: Total T4 level was lower in inattentive subtypes than other subtypes. But, thyroid hormones level showed no difference between ADHD children and control. Also, they have lower total and performance IQ than healthy ones. Children with ADHD were exposed to abuse more than healthy children especially in hyperactive and combined subtypes.