Recognition of early cognitive impairment in Parkinson´s disease (PD) is important since it represents a risk factor for developing Parkinson’s disease dementia and psychosis. The Mini-Mental State Examination (MMSE) remains the most commonly used screening instrument for global cognition, even though it has not been specifically validated for use in PD subjects. More recently, the Montreal Cognitive Assessment (MoCA) test has been recommended as a better screening tool in PD. Most of these studies have been done in countries with a highly-educated population. The objective of the study is to compare the performance between the MMSE and the MoCA to screen for mild cognitive impairment in subjects with Parkinson’s disease and a low education background. The MMSE and MoCA were applied to 128 subjects using a cut-off score of 26 points for cognitive impairment. Fifty-five percent were classified with cognitive impairment according to the MoCA. Forty-one percent of subjects with a normal MMSE were classified with cognitive impairment by MoCA. Results from our analysis could be directly applied to other populations with a high proportion of poorly educated subjects.