Creation of arteriovenous fistulae provides readily available vascular access for haemodialysis in patients with end-stage renal disease. However, it is associated with various potentially serious complications if left unattended. We report a case of a 73-year-old male presenting with an enormous brachio-cephalic fistula aneurysm measuring 70-5.4 cm 20 years after successful renal transplantation. Despite attending regular renal outpatient clinic follow-up, this was only noticed as an incidental finding when the patient attended the emergency department after a fall that severely bruised his access. The patient subsequently underwent ligation with complete removal of the aneurismal fistula and discharged to a rehabilitation unit 3 days post-operatively. Systematic closure of an arteriovenous fistula should be considered in all patients after successful renal transplantation to avoid potentially catastrophic complications of an arteriovenous fistula. In patients in whom the closure of vascular access is contraindicated, it is crucial to regularly assess the status of any arteriovenous fistula when following up patients after renal transplantation.