Anoscrotal fistula is an extremely rare condition involving an epithelialised tract between the anal canal and scrotal wall. It is more commonly seen as a congenital phenomenon in the paediatric population, and has not previously been described in the literature in adults. We present the case of a man aged 52 years who developed a complex anoscrotal fistula after a radical inguinal orchidectomy for an intratesticular seminoma. A postsurgical wound-site infection developed into a chronically discharging wound refractory to antibiotic treatment prompting further investigation. By way of MRI, a 10 cm long trans-sphincteric anoscrotal fistula was found. The patient was successfully treated by fistuloscopic curettage, internal closure using an Ovesco clip, and negative pressure dressing. We present for the first time a rare anoscrotal fistula in an adult.