Background: Very few studies have utilized specific criteria to assess mental disorders in Brain tumor patients. This study aimed to diagnose mental disorders in this population using DSM-IV (depression, sleep, and mood) criteria.Methods: From March 2007 to July 2009, the surgically treated patients with intracranial neoplasm were included in the study. These patients were examined in an ambulatory neuro-oncology clinic setting using a structured psychiatric interview which followed current DSM-IV diagnostic criteria.Results: This study is based on the clinical data of 89 patients with Brain tumor. The mean age was 42.2 years old. Fifty five percent (55 %) of the patients were male. In our study, the prevalence of mild depression was about 30% for males and 38% for females. Before tumor operation, severe anxious as well as severe obsessive-compulsive symptoms were present in 14% of males. In females, 29% of the subjects had reported to have severe anxiousness and 25% severe obsessive symptoms.Conclusion: Depressive symptoms as well as anxious and obsessive psychopathology were shown to be prevalent signs among patients with Brain tumor. The associated factors are tumor location, patient’s premorbid psychiatric status, cognitive symptoms and adaptive or maladaptive response to stress.