Introduction: Parkinson’s disease (PD) is associated with a wide range of cognitive, psychological, and behavioral impairments that significantly affect the life quality of patients and their relatives. Nowadays, it has been observed that prognosis and the stage of the PD could be identified by Frontal Assessment Battery (FAB) via measurement of the abnormality in executive function. FAB test is a brief and precise test. There is a correlation between this test and the other diagnostic tests for PD, such as Unified Parkinson’s Disease Rating Scale (UPDRS) that is time consuming. Therefore, the aim of this study was to measure FAB and UPDRS scores and to determine the possible correlation between these tests. Materials and Methods: Forty-nine patients diagnosed with PD and 50 healthy controls were included in the study. We compared FAB scores in normal controls and in PD patients, which were matched for age, sex, UPDRS, education and Mini-Mental State Examination score. Results: The results indicated a correlation between FAB and UPDRS tests in early stage of PD in all patients while there was no correlation between these two tests in men and women groups separately. Conclusion: FAB diagnostic test is not an appropriate alternative for UPDRS in Iranian Patients with early stage of PD. It is needed to provide a proper version of this test for the Iranian patients based on Persian language and culture.