A retroaortic left renal vein (RLRV) is the term applied to a left renal vein that passes posterior to the abdominal aorta. Typically, the left renal vein traverses horizontally, passing anterior to the abdominal aorta and inferior to the superior mesenteric artery (SMA), before draining into the medial side of the inferior vena cava (IVC). Here, we present a case highlighting type I of the four distinct retroaortic variations observed in the left renal vein. Its prevalence is often underrepresented in medical education despite a clinically significant prevalence in the general population. It is crucial to possess preoperative awareness of this variant to mitigate potential complications linked to vascular damage to the RLRV. These complications encompass severe hemorrhage, renal injury, the necessity for nephrectomy, and, in extreme cases, fatal outcomes during retroperitoneal surgery or interventional procedures. This case report aims to emphasize the significance of incorporating RLRV anomalies into medical education to improve clinical awareness and diagnostic accuracy. The RLRV discussed in this case report was discovered posthumously in an anatomical donor.