It is difficult to differentiate acute skin failure (ASF) from pressure ulcer (PU). ASF is defined as unavoidable injury resulting from hypoperfusion caused by severe dysfunction of another organ system. We describe a case of ASF mistaken as PU that resulted in a legal dispute. A 74-year-old male patient was admitted to our intensive care unit with sepsis due to bacterial pneumonia. Despite the use of air cushions and regular position changes, skin ulcerations occurred over his occiput, back, buttock, elbow, and ankle. After improvement in his general condition, he was transferred to the department of plastic and reconstructive surgery. Debridement was performed immediately, followed by conservative treatment (including a vacuum-assisted closure device) for 6 weeks. The buttock and occiput wounds were treated surgically. Despite complete healing, his caregivers sued the hospital for failing to prevent PU formation. ASF is a pressure-related injury resulting from hemodynamic instability due to organ system failure. Unlike PU, ASF may occur despite the implementation of all appropriate preventive measures. Furthermore, misdiagnosis of ASF as PU can lead to litigation. Therefore, it is critical for the proper diagnosis to be made quickly, and for physicians to explain that ASF occurs despite proper preventative treatment.