Background: Pressure injuries impact both patients and healthcare organisations. Implementing pressure injury prevention strategies reflects current clinical practice guidelines, but in Australia, evidence on the factors that predict the implementation of these strategies is lacking. Aim: To determine the patient, clinical and contextual factors that predict the implementation of pressure injury prevention strategies among acute medical patients with reduced mobility at two Australian hospitals. Method: An observational study using chart audits and semi-structured observations. A consecutive sample of 241 participants (patients) was recruited from four medical units at two large Australian hospitals. Multiple logistic regression and multiple regression analyses were performed to identify predictors of support surfaces, regular repositioning, patient education and the number of pressure injury prevention strategies. Results: Only 113 (46.9%) participants had a pressure injury risk assessment undertaken on admission. Regular repositioning was the most frequent, and often the only implemented strategy. Two factors predicted the implementation of support surfaces: participants identified at pressure injury risk during hospitalisation, and their 24-h activity. As a participant's mobility decreased, there was a 6% increase in the implementation of support surfaces (p = 0.001) such as pressure-relieving mattresses. Participants identified at pressure injury risk were more likely to receive prevention education. Conclusion: Participants identified at pressure injury risk were most likely to receive prevention strategies. The low-pressure injury risk assessment rates mean some patients may not receive the recommended preventive care. There seems to be a reliance on a single prevention strategy, rather than a suite of them.