Arteriovenous fistulas (aVF’s) have emerged as the preferred method for haemodialysis due to their longevity and reduced infection risk in comparison to other access methods. Despite careful surgical selection and close postoperative evaluation, many fistulas undergo failure to mature (primary failure) or loss of a previously functional aVF (secondary failure). These need to be recognised early to consider surgical or endovascular intervention to prevent permanent aVF loss. We present real-world case-based series from a tertiary centre across different ages, sexes and ethnicities. We demonstrate common anatomical sites of dysfunction including the juxta-anastomotic segment, outflow vein and less commonly the central vein. We provide insight into clinical and imaging features that can predict primary fistula failure including the rule of 6’s of blood flow >600mL/min, vein diameter >6mm and depth <6mm. In contrast, secondary fistula failure can be sudden, and surgical residents are key to recognising loss of continuous thrill, reduced bruit, increased venous pressures during dialysis and reduced dialysis capacity. Causes of secondary failure can be determined with imaging: Stenosis secondary to intimal hyperplasia at the juxta-anastomotic segment or sites of previous central access are identified with Peak Systolic Velocity Ratios >2 and post stenotic turbulent flow. Additionally, echogenic intraluminal material or saccular dilatation on ultrasound can also suggest thrombus or pseudoaneurysm formation which are less common, although clinically significant causes of secondary failure. Teaching on subspecialised domains such as aVF is limited for many surgical residents. As typically the first responders, recognising the clinical and imaging features of fistula failure can allow for timely consideration of surgical or endovascular evaluation to prevent permanent fistula loss.