IntroductionPeople with parkinsonism are a highly heterogeneous group and the disease encompasses a spectrum of motor and non-motor symptoms which variably emerge and manifest across the disease course, fluctuate over time and negatively impact quality of life. While parkinsonism is not directly the result of ageing, it is a condition that mostly affects older people, who may also be living with frailty and multimorbidity. This study aims to describe the broad range of health needs for people with parkinsonism and their carers in relation to their symptomatology, disability, disease stage, comorbidities and sociodemographic characteristics.Methods and analysisIn this single site cross-sectional study, people with parkinsonism will be sent a study information pack for themselves and their primary informal caregiver, if relevant. Data are collected via questionnaire, with additional support, if required, to maximise participation. A specific strategy has been developed to target and proactively recruit patients lacking capacity to consent, including those in residential care settings, with input from a personal consultee prior to completion of a bespoke questionnaire by a representative. Caregivers are also recruited to look at various health outcomes. Results will be displayed as descriptive statistics and regression models will be used to test simple associations and interactions.Ethics and disseminationThis protocol was approved by the London—Brighton & Sussex Research Ethics Committee (REC reference 20/LO/0890). The results of this protocol will be disseminated through publication in an international peer-reviewed journal; presentation at academic meetings and conferences; and a lay summary uploaded to the PRIME-Parkinson website.Trial registration numberISRCTN11452969; Pre-results.