fa پژوهشي اصیل Original Research <strong>Background and Objectives:</strong> Attention Deficit/Hyperactivity Disorder (ADHD) occurs concurrently with&nbsp;many psychiatric disorders. Considering lack of information about comorbid psychiatric disorders in Iranian&nbsp;children, this study was performed to evaluate the prevalence and pattern of psychiatric disorders comorbidity in&nbsp;the children with ADHD.<br> <strong>Methods:</strong> In a cross sectional study, frequency of comorbid psychiatric disorders in a randomly selected&nbsp;sample of children with definitive ADHD referred to child and adolescent psychiatry clinic of Kashan University&nbsp;of Medical Sciences, Iran, was determined through clinical interview using Kiddie&#39;s Schedule for Affective&nbsp;Disorders and Schizophrenia.<br> <strong>Results:</strong> The mean age of participating children was 7.35&plusmn;1.23 years and 132(66%) children were boy.&nbsp;Among 200 children, 107 (53.5%) had at least one comorbid psychiatric disorder which Obsessive-Compulsive&nbsp;Disorder was most prevalent psychiatric disorders following with Enuresis, and Oppositional Defiant Disorder<br> respectively. There were statistically significant relationships between age and the type of comorbid psychiatric&nbsp;disorders.<br> <strong>Conclusion:</strong> Considering the high prevalence of psychiatric disorders comorbidity such as OCD, Enuresis&nbsp;and ODD in children with ADHD, precise diagnosis and proper treatment is essential. More studies are recommended&nbsp;for detection and proper treatment of these psychiatric disorder comorbidities. Attention Deficit Hyperactivity Disorder, Comorbidity, Psychiatric Disorder 14 19 http://ijca.iums.ac.ir/browse.php?a_code=A-10-1-55&slc_lang=fa&sid=1 Zahra Sepehrmanesh z.sepehrmanesh@gmail.com 1003194753284600428 1003194753284600428 Yes Kashan University of Medical Sciences, Kashan, Iran.