Background: Obsessive-compulsive disorder (OCD) symptoms and the related disorders are subsumed under chronic psychiatric disorders which are of psychosocial and therapeutic importance. In most studies, the mean age of onset of significant OCD symptoms is adolescence period. The aim of this study was to evaluate OCD symptoms, Tic disorder, Body Dysmorphic Disorder (BDD) and Trichotilomania among middle school students inShiraz,Iran. Method: From the four educational district of Shiraz, South of Iran, 1682 middle school students, aged 14-16 yrs-old, were selected using a cluster random sampling. Persian standardized Moudsely Obsessive-Compulsive Inventory was used to assess obsessional symptoms. For evaluating BDD, Tic Disorder and Trichotilomania symptoms, a semi-structured interview was done according to Diagnostic and Statistical Manual-IV-TR (DSM-IV-TR) criteria. Results: Students with more obsessional symptoms were mostly girls and showed more positive family history. They were more likely from low socioeconomic class, and their average school grades were lower. They also showed high association with BDD and Tic disorders. Conclusion: This study confirmed body dysmorphic and Tic disorders to be more prevalent in individuals with obsessive-compulsive disorder symptoms. Girls, especially those from lower socioeconomic class, demonstrated increasing obsessional symptoms. Obsessive-compulsive disorder symptoms were found to affect school performance so its early diagnosis and management should be considered as a mental health priority.