Introduction Several studies have shown that physical activity (PA) levels and sedentary behaviour (SB) are independent risk factors for many health-related issues. However, there is scarce evidence supporting the relationship between SB and urinary incontinence (UI) in community-dwelling older adults, and no information on any possible association in institutionalised older adults. Stage I of this project has the main objective of determining the prevalence of UI and its associated factors in nursing home (NH) residents, as well as analysing the association between UI (and its types) and SB. Stage II aims to investigate the incidence and predictive factors of functional and continence decline, falls, hospitalisations, mortality and the impact of the COVID-19 pandemic among NH residents. Methods and analysis Stage I is an observational, multicentre, cross-sectional study with mixed methodology that aims to explore the current status of several health-related outcomes in NH residents of Osona (Barcelona, Spain). The prevalence ratio will be used as an association measure and multivariate analysis will be undertaken using Poisson regression with robust variance. Stage II is a 2-year longitudinal study that aims to analyse functional and continence decline, incidence of falls, hospitalisations, mortality and the impact of the COVID-19 pandemic on these outcomes. A survival analysis using the actuarial method for functional decline and continence, evaluated every 6 months, and the Kaplan-Meier method for falls, hospitalisations and deaths, and Cox regression for multivariate analysis will be undertaken. Ethics and dissemination The study received the following approvals: University of Vic-Central University of Catalonia Ethics and Research Committee (92/2019 and 109/2020), Clinical Research Ethics Committee of the Osona Foundation for Health Research and Education (FORES) (code 2020118/PR249). Study results will be disseminated at conferences, meetings and through peer-reviewed journals.