The development of Fournier's gangrene in an 80-year-old male patient with diabetes after a routine outpatient haemorrhoid banding procedure is described. Four days following the procedure, the patient noticed an increasing amount of pain and swelling of the perianal region. When the patient presented to the emergency department 18 days later, immediate radical debridement of ischiorectal necrotic tissue was performed. A defunctioning loop sigmoid colostomy was also formed. Subsequent operations required excision of the scrotum and abdominoperineal excision of the rectum. Histology studies later confirmed the presence of necrotising fasciitis. The case acts as a reminder that clinicians should maintain a high index of suspicion for high-risk patients still suffering from problems following the procedure.