Malnutrition is frequently undetected in care homes. It is recommended that residents are screened on admission and at suitable intervals thereafter. It is aimed to implement the ‘Malnutrition Universal Screening Tool’ (‘MUST’) in all care homes in Norfolk in order to fulfil this recommendation. Following a pilot of successful (but time-consuming) ‘MUST’ training a train-the-trainer package was developed as a practical way of achieving this goal. Courses were held in 2007, each comprising a study day and an assessment of each trainer delivering training. Trainers were provided with a dossier of training support materials. Data were collected at the study day and 3 months after the course to evaluate its effectiveness. Sixty-seven trainers were trained, all of whom rated the course as effective in preparing them to deliver training. At their assessments 96% were able to explain ‘MUST’ accurately. Of the new trainers 44% returned follow-up questionnaires and copies of sample care plans. The majority of care plans showed ‘MUST’ scores had been calculated accurately and appropriate nutrition care plans had been set up and evaluated. The train-the-trainer model is an effective method of training large numbers of care-home staff to use ‘MUST’. One of the unexpected benefits observed was the ownership taken by the trainers, which was demonstrated by the enthusiasm and confidence with which they subsequently trained their colleagues.