Perianal abscess and fistula are 2 distinct entities that share a common pathology. A horseshoe fistulous abscess, a complex type of these conditions, occurs when the suppurative inflammation spreads through the deep anal space to the bilateral ischiorectal fossae. Following the intersphincteric plane, this infection may extend to the pararectal space, forming a supralevator abscess. We present a very rare case involving a 52-year-old male patient who was admitted to our surgical department with an extraperitoneal purulent inflammation as a complication following multiple drainage procedures for a posterior horseshoe abscess. Emphasis is given to the anatomical and technical considerations of eradication of anorectal sepsis and the management of complex fistula-in-ano along with a concise review of the literature.