The study aimed to examine the reliability and validity of the Turkish version of the Montreal Cognitive Assessment Scale (MoCA-TR) as a screening tool for cognitive dysfunction in Parkinson's disease (PD). A total of 50 patients with PD and 50 healthy controls were included. The screening instrumentsMoCA-TR followed by the Mini-Mental Status Examination (MMSE-TR) and MoCA-TR retest within 1 monthand detailed neuropsychological testing were administered to the PD patients. MoCA-TR and MMSE-TR were also administered to controls. The discriminant validities of the MoCA-TR and MMSE-TR as screening and diagnostic instruments were ascertained. The concurrent and criterion validity, test-retest reliability, and internal consistency of the MoCA-TR and MMSE-TR were examined. The Cronbach's alpha of the MoCA-TR as an index of internal consistency was 0.664, and the test-retest reliability of MoCA-TR was 0.742. With a cut-off score of < 21 points, the MoCA-TR showed sensitivity of 59% and specificity of 89% in the detection of cognitive dysfunction in PD. The area under the receiver-operating characteristics curve (95% confidence interval) for MoCA-TR was 0.794 (0.670-0.918), p<.001. The present results indicated that the MoCA-TR has acceptable psychometric properties and it should be used to assess mild cognitive impairment and early dementia in PD patients, whereas the MMSE-TR should remain the instrument of choice to assess cognitive impairment in PD dementia.