IntroductionParkinson’s disease is a motor disease, the second most common neurodegenerative disorder with cardinal symptoms including bradykinesia, rigidity, and rest tremor accompanied by cognitive difficulties. The caregivers play a crucial role for individuals with Parkinson’s disease; however, many of them may suffer from high caregiver burden and mental health deterioration. This protocol of a systematic review presents a methodology of the review about the impact of cognitive impairment of individuals with Parkinson’s disease on their caregivers’ mental health.Material and methodsResearch will be identified by combining electronic databases searching and hand searching. The following databases will be included: Medline, PsycInfo, Web of Sciences, Cochrane, CINAHL, Embase and Scopus. The inclusion and exclusion criteria followed to PECOS model. The population of informal caregivers is defined as family members providing care on a patient with Parkinson’s disease. Exposure is linked with the evaluation of a cognitive functioning and outcome is defined as mental health among caregivers of individuals with Parkinson’s disease. We will include two types of studies: observational and intervention. Both, screening and eligibility will be done by two independent reviewers. Study quality will be assessed by two authors independently. Data will be extracted by two reviewers independently and will follow a pre-pilot extraction form. Any discrepancies will be resolved by discussion or/and consultation with another reviewer. The synthesis without meta-analysis (SWiM) guidelines will be used to report on included studies data. The metanalysis with usage the statistical software R version 4.1.2 (2021-11-01) “Bird Hippie” and R metaphor package 3.0–2 of will be conducted if possible.DiscussionThe goal of this systematic review is to present the association between caregivers’ mental health problems and their proteges’ cognitive impairment. It will enable to identify the gaps in literature and its methodology giving the suggestions for further research.Protocol registrationProtocol registration number in PROSPERO: CRD42022296670