Mild cognitive impairment associated with Parkinson's disease (PD) is a risk factor for the development of dementia. Despite the importance of early identification of mild cognitive impairment in PD, its prevalence and clinical correlates are still debated. The present meta-analysis provides a robust estimate of prevalence rate of mild cognitive impairment in PD according to the Movement Disorder Society clinical criteria and to explore the differences between PD patients with and without mild cognitive impairment in demographic, clinical, and neuropsychiatric features. A systematic literature search was performed up to April 2019 using PsycInfo (PROQUEST), PubMed, and Scopus. From 4706 titles and abstracts, 41 studies were selected (n = 7053 patients). Pooled mild cognitive impairment prevalence was 40% on a total sample of 7053 PD patients (95% confidence interval = 36–44; Q = 490.14, P
