Background: Evidence exists on how to prevent pressure ulcers, malnutrition, poor oral health and falls among older persons in nursing homes, but these health risks still occur frequently, causing suffering. Aim: The overall aim of the thesis was to develop and evaluate the feasibility of an educational intervention to prevent pressure ulcers, malnutrition, poor oral health and falls among older persons in nursing homes. Methods: By combining methods, four studies were conducted to develop and evaluate the feasibility of an educational intervention. The educational intervention was developed in studies I-III, and its feasibility was evaluated in study IV. In study I, a quantitative study was conducted to determine the prevalence of the risks of pressure ulcers, malnutrition, poor oral health and falls among older persons receiving municipal healthcare. In study II, a qualitative study was conducted to explore nurse aides’, registered nurses’ and managers’ experiences of preventive work regarding pressure ulcers, malnutrition, poor oral health and falls among older persons in nursing homes. In study III, a qualitativ estudy was conducted to co-design the educational intervention together with nurse aides, registered nurses and managers to prevent pressure ulcers, malnutrition, poor oral health and falls among older persons in nursing homes. Additionally, key persons in the municipality participated in co-designing the educational intervention. The development process and the educational intervention itself was also described in study III. In study IV, a mixed methods study was conducted to evaluate the feasibility of the educational intervention. Results: The risks of pressure ulcers, malnutrition, poor oral health and falls was approximately 28%, 56%, 34% and 74%, respectively, and approximately 90% had at least one health risk (study I). Nurse aides, registered nurses and managers experienced prevention of pressure ulcers, malnutrition, poor oral health and falls as important but challenging (study II). The lack of knowledge among them was reported as a major challenge (studies II and III). The educational intervention, the STAIR OF KNOWLEDGE, was co-designed with nurse aides, registered nurses and managers in nursing homes, and stakeholders in the municipality, to prevent pressure ulcers, malnutrition, poor oral health and falls among older persons in nursing homes. The content, format and delivery of the STAIR OF KNOWLEDGE intervention was co-designed to fit the need for knowledge to prevent pressure ulcers, malnutrition, poor oral health and falls among older persons in a local context (study III), and was proven as feasible but with some refinements required for a perfect fit (study IV). Conclusion: The educational intervention, the STAIR OF KNOWLEDGE, was developed together with and for nurse aides, registered nurses and managers to prevent pressure ulcers, malnutrition, poor oral health and falls among older persons in nursing homes. The STAIR OF KNOWLEDGE intervention is therefore likely to provide end users with the knowledge needed to accomplish preventive work in nursing homes. The STAIR OF KNOWLEDGE intervention was proven to be feasible but with some amendments necessary before continuing to a definitive trial.