Pressure sores (decubitus ulcers) are complications feared in nursing practice, and at the same time, the prevention of a decubitus ulcer is a core competence in nursing and an important indicator of good care. Gerhard Schröder, Jan Kottner, and other pressure ulcer experts clarify, define, and classify what a pressure ulcer is. They show how nursing staff can recognize a pressure ulcer or assess pressure ulcer risks, explain why and how a pressure ulcer develops, and describe the significance of pressure ulcers from the perspective of those affected, as well as from epidemiological and economic viewpoints. They also describe and demonstrate how nursing staff can prevent a pressure sore through risk assessment, encouragement of movement, and the use of pressure-distributing aids. Additionally, they highlight the role of nutrition and skin care in the context of pressure sore prevention and treatment, and describe how nursing staff can assist patients in this regard.