Community-acquired pneumonia is a serious public health problem, and more so in older patients, leading to high morbidity and mortality. However, this problem can be reduced by optimising in-hospital nursing care. Accordingly, this study describes a systematic process of designing and developing a tailored theory- and research-based implementation strategy that supports registered nurses (RNs) in delivering evidence-based and person-centred care for this patient population in a hospital setting. The implementation strategy was developed by completing the six steps of the Intervention Mapping framework: (1) developing a logic model of the problem and (2) a logic model of change by defining performance and change objectives, (3) designing implementation strategy interventions by selecting theory-based change methods, (4) planning the interventions and producing materials through a co-design approach, (5) developing a structured plan for adoption, maintenance and implementation and (6) developing an evaluation plan. This method can serve as a guide to (1) target behavioural and environmental barriers hindering the delivery of nursing care in local clinical practice, (2) support evidence uptake, (3) support RNs in the delivery of nursing care according to individual patient needs and thereby (4) optimise health-related patient outcomes.