Situation awareness (SA) has been developed in occupations other than nursing to improve decision making (DM) for optimal performance and outcomes. There are some studies exploring the use of situation awareness by nurses in simulated settings but few have examined SA in clinical practice. Because of this paucity of evidence nurses’ use of situation awareness in practice is not fully understood. Studies examining decision making by nurses have indicated that clinical decisions arising from a lack of awareness of patient needs in busy, complex clinical environments can compromise care. In ward environments, compromised care often results in the omission of ‘basic’ nursing interventions which may include pressure injury prevention. This thesis explored the use of situation awareness by nurses in medical/surgical wards as the precursor to decision making and the influences on situation awareness whilst making pressure injury prevention decisions in practice.