Supralevator fistula stays a challenge in general surgery. We present a case with supralevator anorectal fistula and subsequent retroperitoneal necrotizing fasciitis in which autologous platelet-rich plasma and platelet-rich fibrin glue were used for fistula closure. A 59-year-old man was admitted with pelvic pain and fever. Abdominopelvic sonography and CT scan reported a deep horseshoe-shaped anorectal abscess with extension to the pelvic floor, supralevator, psoas, retroperitoneal muscles, and kidneys. He was managed with antibiotics, abscess drainage, repeated radical surgical debridement, and necrosectomy. After 30 days, he was discharged, but he returned to the office with the complaint of purulent discharge from the hypogastric region and a diagnosis of fistula formation. Platelet-rich plasma was injected around the fistula into the tissue, and platelet-rich fibrin glue was introduced to the fistula tract. At the 11-month follow-up, the patient did not have voiding dysfunction, constipation, diarrhea, or fistula tract infection. Autologous platelet-rich plasma injection and platelet-rich fibrin glue insertion suggest a secure and effective approach for treating supralevator anorectal fistula.