Aim: To highlight and discuss the presentation, diagnosis and management of a complex uretero-arterial fistula following a penetrating trauma. Background: Uretero-arterial fistulas are a rare but dangerous connection, usually between the ureter and iliac artery. Gunshot wounds to the abdomen usually result in injuries to multiple intraabdominal structures. Despite a normal appearing ureter, delayed necrosis and subsequent fistulization can occur following a penetrating trauma. Patients may present with life-threatening hemorrhage and diagnosis is often imprecise. Case description: We report the case of a 52-year-old male who presented with a single gunshot wound to the right lower abdomen and was found to have multiple enterotomies as well as a right iliac vein injury. Although the ureter appeared uninjured during the intraoperative assessment, the patient developed a urine leak two weeks after the injury. A ureteral stent and nephrostomy tube were placed to facilitate healing and divert urine. However, the patient re-presented 46 days after initial injury with significant hematuria and diagnosis of a uretero-arterial fistula. Conclusion: Penetrating traumas, especially blast injuries such as gunshot wounds, have a higher risk for delayed injuries secondary to tissue devascularization or necrosis. Ureteral vascular supply is especially delicate and clinicians should have a high suspicion for delayed ureteral complications when a blast injury occurs nearby. It is important to maintain a low threshold for pre-emptive ureteral stenting or excision and repair of an at-risk segment even when the ureter appears intact on initial inspection. Clinical significance: Uretero-arterial fistulas can be fatal, especially as its presentation often occurs suddenly, with large volume blood loss, and diagnosis can be difficult. Prompt and appropriate treatment requires a high level of suspicion and awareness of its potential.