IntroductionThe increase in elderly population has led to an associated increase in multiple pathologies, frailty, polypharmacy, healthcare costs, decreased quality of life and mortality. We designed an intervention based on person-centred care model. This article outlines a study protocol, which aims to explore the effects of the intervention to improve therapeutic adequacy in polymedicated elderly patients.Methods and analysisAn open, randomised, multicentre, controlled clinical trial. The study population includes polymedicated (≥8 prescription medications) patients ≥75 years old. In the intervention group, the multidisciplinary team (primary care pharmacist, family doctor and nurse) will meet to carry out multidimensional reviews (frailty, clinical complexity, morbidity and therapeutic adequacy) of the study subjects. If changes are proposed to the treatment plan, a clinical interview will be conducted with the patient to agree on changes in accordance with their preferences. Follow-up visits will be scheduled at 6 and 12 months. In the control group, where the usual clinical practice will be followed, the necessary data will be collected to compare the results.The key variables are the variation in the mean number of incidents (potentially inappropriate prescription) per patient, the number of medications, the number of changes implemented to the treatment plan and the variation in the number of hospital admissions.Ethics and disseminationThis study was approved by the Ethics Committee of the IDIAPJGol and by the University of Barcelona’s Bioethics Commission. The results are expected to be published in peer reviewed open-access journals, and as part of a doctoral thesis.Trial registration numberNCT04188470. Pre-results.