Introduction & Objective: The aim of this research was to review the constitutional and other risk factors in children with Attention Deficit and Hyperactivity Disorder (ADHD).

Materials & Methods: Present research was a descriptive–comparison and subjects were 180 children with ADHD. 210 matched healthy children participated as a control group. Questionnaire was designed by the researcher.

Results: Results showed that the rate of temperamental and learning disorder type in children of subject group, and the history of learning disorder, attention deficit and hyperactivity disorder in parents and relatives of subject group were more than control group.

Conclusion: On the basis of results it was determined that constitution factors more than environmental factors have great effect in ADHD. These finding support the results of previous researches.