Pressure ulcers are painful, costly and can negatively affect a patient’s quality of life. It has long been recognised that they increase the risk of infection, prolong hospital stays and can result in death. To prevent the occurrence of pressure ulcers, nurses need to understand what a pressure ulcer is and the underlying factors that cause them. Furthermore, it is essential that they recognise why some people are more susceptible to pressure and shear forces than others, so that preventable factors can be addressed. Nursing care to prevent pressure ulcers needs to be planned, implemented and evaluated in a systematic manner following an assessment of the patient and their circumstances. The ‘aSSKINg’ (assess risk; skin assessment and skin care; surface; keep moving; incontinence and moisture; nutrition and hydration; and giving information or getting help) model ensures all fundamental aspects of pressure ulcer prevention are included in patient care. This article outlines the definitions and causes of pressure ulcers, and explains how nurses can assess, plan, implement and evaluate pressure ulcer preventative care using the aSSKINg model as a guide.