We report two cases of iatrogenic occlusion of the superior mesenteric artery (SMA) and celiac axis (CA) during left nephrectomy. A patient with a urothelial carcinoma (open surgery) and one with coralliform calculi (laparoscopy) experienced injury to both the SMA and/or CA due to bulky perihilar adenopathy and kidney adherence to surrounding tissue. The cancer patient survived after fast repair. Repair was delayed in the second patient who subsequently died. It is essential to identify each arterial branch carefully on the preoperative CT-scan to identify any duplicate renal arteries and avoid mistaking the SMA and/or CA for the renal artery.