We report a case of severe sacral osteomyelitis and sepsis with pressure ulcer infection treated with negative pressure wound therapy with instillation and dwelling (NPWTi-d) V.A.C.ULTA® from an early stage. Case: A 76-year-old man, bedridden because of dementia and an old cerebral infarction, was treated in a nursing facility for a sacral region pressure ulcer. He had a fever for three days and was transferred to the emergency department. The quick SOFA (sequential organ failure assessment) score at the hospital visit was three points. A coccyx and black mud-formed necrotic tissue attached to the sacral region pressure ulcer with a strong putrid odor sloughed off. Sacral region pressure ulcer infection, sepsis, disseminated intravascular coagulation, and purulent sacral osteomyelitis were diagnosed, and urgent debridement was performed. We treated the patient with meropenem, clindamycin, and vancomycin, and we performed irrigation debridement every day and transduced the V.A.C.ULTA® care system from AOD9, that led to good granulation at the infection site. The wound area underwent simple closure on AOD35 and the patient was transferred to the medical treatment hospital. Since dressing change is relatively easy in the emergency department of a secondary medical care institution with little man power, V.A.C.ULTA® therapy may be useful in treating severe cases of pressure ulcer infections.