Background: In hospital settings, delirium affects as many as 50% of older patients, aggravating their symptoms and worsening their condition, and therefore increasing the risk of in-hospital complications and death. The aim of this study is to assess the efficacy of structured, non-pharmacological care, delivered to older hospitalised patients by trained volunteers (students of medical fields), on the reduction of incidence of adverse health-related outcomes. Methods/design: This trial will be a randomised, investigator-blind, controlled trial conducted in an internal medicine and geriatric ward in Poland. We aim to include 416 patients who are 70 years of age and have been hospitalised for medical reasons. Eligible patients will be randomised 1:1 to receive structured, non-pharmacological care delivered by students of medicine, psychology and nursing, together with standard medical treatment or standard medical care alone. The protocol of interventions has been designed to cover nine main risk factors for delirium, with the scope of multidisciplinary interventions being individualised and tailored. The protocol will be aimed at immobilisation, vision and hearing impairment, cognitive impairment and disorientation, stress and anxiety, sleep–wake cycle disturbances, dehydration and malnutrition, and pain. A structured evaluation of patients’ cognition, mood, anxiety and functional performance is planned to be carried out twice, on the day of group allocation and at discharge; structured screening assessment for delirium will be conducted daily using the Confusion Assessment Method. The primary outcome will be the incidence of delirium in hospital; secondary outcomes will be in-hospital changes in cognition, mood and anxiety, and functional status, occurrence of falls and death. Discussion: Delirium prevention programmes are being introduced worldwide. A particular novelty of our project, however, is that invitations for voluntary work with older patients at risk for delirium will be addressed to medical students. With the use of the service learning method, the students will shape their attitudes, increase their knowledge and understanding of hospital care, and master competencies to work within interdisciplinary teams, which establishes the originality and practicality of the project.