The first intervention in pressure ulcer prevention is often the completion of a pressure ulcer risk assessment, which aims to identify a patient’s level of risk of developing a pressure ulcer. Appropriate care planning should then follow. There are several pressure ulcer risk assessment tools that nurses can use in their clinical practice, but it has not always been clear which is the most effective. One of these tools – the PURPOSE T (Pressure Ulcer Risk Primary or Secondary Evaluation Tool) – has recently been recommended in national guidelines and is now considered to be the only tool with an up-to-date evidence base. This article examines some of the risk assessment tools used to assess pressure ulcer risk, as well as providing an overview of the PURPOSE T and explaining its significance in pressure ulcer prevention.