Aortocaval fistula is an abnormal vascular communication between an aortic aneurysm and the inferior vena cava. The condition is very rare and life threatening with high mortality. This article reports a case of aortocaval fistula in a 76-year-old male diagnosed using computed tomography. Computed tomography, being a non-invasive investigation, ensures early diagnosis and can help in prompt surgical or interventional radiological management which can be life-saving.