Background &objectives: Today many theorists in etiology of attention deficit/hyperactivity disorder (ADHD) believe that a deficit in behavioral inhibition is a cause of appearing the symptoms of this disorder. Thus the frequency of high-risk behaviors in people with this disorder is expected to be remarkable. Therefore, the aim of this study was to compare the high-risk behaviors in students who are sufferers and the non- sufferers of ADHD.

Methods: The study was descriptive and causal-comparative. The population included all students studying in the academic year 2015-16 at Ferdowsi University of Mashhad. Among them two groups, with and without ADHD were selected through the convenience sampling method. There were 23 people in each group and this sample size was determined by Gpower application. Structural clinical interview for DSM-IV-TR (SCID-I), Barkley Adult ADHD Rating Scale-IV and risk-taking scale were used for data collection. Data analysis was performed using multivariate analysis of variance in SPSS-18.

Results: The findings showed that students with ADHD had more high-risk behaviors in dangerous driving, tendency to violence (p=0.01) and a tendency to sexual risk-taking (p=0.05) compared with those without this disorder. But there was not a significant difference among them in other high-risk behaviors.

Conclusions: According to the results, it can be concluded that high-risk behaviors are more common in students with ADHD compared with those without this disorder.