There is increasing evidence that the use of arterial conduits for coronary artery bypass grafting provides superior long-term results when compared to using saphenous veins alone. Major complications of using internal thoracic arteries (ITAs) and inferior epigastric arteries (IEAs) are uncommon. We report the case of a 42-year-old man who underwent coronary revascularisation in which harvesting of these arteries resulted in critical ischaemia of the lower limbs requiring aortobifemoral grafting. This patient had a long-standing occluded abdominal aorta which was asymptomatic and relied on the ITAs and IEAs as important collateral blood supply to the legs. The enormous size of these conduits found at operation suggested their role. Management strategies to avoid such a serious complication are discussed.