Necrotizing fasciitis (NF) is a life-threatening infection, which requires immediate debridement and broad-spectrum antibiotic treatment. Delay in prompt diagnosis and operative debridement is associated with significant morbidity and mortality. Retroperitoneal NF is a rare condition whereby the infection within the pelvis or retroperitoneum rapidly expands over the fascial planes to involve the anterior abdominal wall (AW), the thighs and the buttocks. It presents a challenge for surgical access due to the anatomic depth of the structures and may result in extensive soft tissue loss requiring complex AW reconstruction for closure. The case discussed here is a 43-year-old female with a perianal abscess that progressed to retroperitoneal and anterior AW NF with intra-peritoneal abscess collection requiring bilateral tensor fascia-lata graft for the closure of the anterior AW fascia defect.