Introduction: Patients with obsessive compulsive disorder (OCD) have impaired cognitive functions, including attention, verbal and visual memory, and visual-spatial abilities as well as executive function But some studies did not show any disturbance in executive function of patients with OCD. To date, only few studies have been conducted on neuropsychological functioning of patients with panic disorder (PD). There are limited studies to reach a definite conclusion on executive functions of patients with OCD and those with PD. In this study, we aimed to measure executive functions of patients with OCD and those with PD compared with those of healthy controls. Although there are many studies on cognitive functions of patients with OCD, there appears to be no consistency in results and no findings have been obtained to enable us to reach definite conclusions. Although there are very few studies on neuropsychological functions of patients with PD, impairments on a set of cognitive functions have been demonstrated. To date, no finding with respect to impairment in executive functions of patients with PD has been published. PD and OCD are disorders manifesting similar characteristics, with the presence of anxiety and avoidance behavior. Besides this, patients with OCD also have symptoms such as obsessions and compulsions that are characteristics of this disorder. We aim to compare executive functions in the three groups (patients with OCD, those with PD, and healthy controls) in this study.