Background: Executive function (EF) domain deficits which most reported include in particular set shifting and inhibition, which are considered main deficits in obsessive-compulsive disorder (OCD). So, this research aimed to assess EF in patients with a primary diagnosis of OCD in comparison to a healthy control group; in order to understand the impaction of this disorder on the patient’s neuropsychological status. Results: There was no significant difference between OCD patients and controls regarding demographic characteristics. Average duration of illness in OCD group was 3.97 ± 5.08 years. Forty patients (60.6%) had OCD medication prior to the study. Depression was the most prevalent comorbidity among OCD group (36.4%) then anxiety (12.1%) and social anxiety (3%). Regarding WCST indices, a significant difference (P < 0.05) was found between both groups in total number of correct answers, total number of errors, mean of errors, total number of perseverative errors, mean of perseverative errors, total number of non-perseverative errors, mean of nonperseverative errors, and conceptual level responses without significant difference (P ≥ 0.05) in the remaining indices. In ToL indices, there was highly significant difference (P < 0.001) between both groups regarding total time, but not regarding total moves (P ≥ 0.05). The defect in EF was positively correlated to the severity of symptoms of OCD. There was no significant difference between patients who had been receiving medical treatment and those who had not, also between patients who had comorbidities accompanying OCD and those who had not regarding EF as evident by both WCST measured parameters and TOL parameters. Conclusions: OCD patients appear to have EF deficits in the fields of set-shifting, inhibitory control, working memory, and planning ability.