The formation of an appendico-cutaneous fistula is rare. Few case reports have been published; most describe the formation of a fistula after appendicitis. Here we describe the case of a 79-year-old woman presenting with an appendico-cutaneous fistula after groin hernia repair. She was referred to our outpatient department with a painful mass in the right groin. An ultrasound showed a fluid containing mass. Incision and drainage was performed. After 9 weeks she was referred again with a persisting open wound. Fistulogram and CT scan showed a fistuleous tract involving the appendix. Wound culture showed Escherichia coli. Diagnostic laparoscopy showed an appendix stuck to the ventral wall of the abdomen without any sign of previous infection. After an appendectomy, pathological investigation revealed an appendix sana. After operation, the fistula persisted due to a polypropylene plug from the previous groin hernia correction. The (infected) plug was removed and the fistula healed.