Introduction: Necrotizing fasciitis (NF) is an aggressive soft tissue infection that involves the deep fascia and is characterized by the extensive deterioration of the surrounding tissue. Immediate recognition and aggressive treatment, including debridement and systemic antibiotics, are mandatory for the successful management of NF. Following radical debridement, closure of the remaining wound can pose significant reconstructive challenges. Accumulating evidence indicates that application of negative-pressure wound therapy (NPWT) is useful in the treatment of patients with severe acute complex wounds, including NF. Case Presentation: A 58-year-old man who had undergone surgical resection for rectal carcinoma followed by chemo-radiation therapy developed NF of the pelvis and thigh three years after the surgical procedure. Following extensive debridement, a VAC system was applied to the large open wound and successfully contributed to wound bed cleansing, which was followed by surgery for skin grafting. Conclusion: This case demonstrates the successful management of a complex and potentially lethal wound of the perineum to lower leg with debridement and skin grafting as well as with the application of the VAC system.