AIM: Congenital anomalies of the inferior vena cava (IVC) are very rare and extremely diverse, reflecting the complexity of the embryological development of these structures. The variants must be differentiated from pathology, particularly lymphadenopathy, on imaging studies as their presence can affect surgical and interventional procedures in retroperitoneum. We describe two patients with renal cell carcinoma of left kidney and left IVC. CASE REPORT: First patient was taken up for left radical nephroureterectomy. During surgery the existence of a transposed left IVC was demonstrated. The second case is a fifty-four-year-old man; abdomen and pelvic CT-scan with coronal maximum intensity projection reconstruction showed a 7 cm heterogeneously enhancing neoformation involving the left kidney with intraparenchymal hematoma and a transposed left IVC. CONCLUSIONS: Preoperative detection of congenital IVC anomalies can prevent morbidity. Once diagnosed, appropriate care must be taken during the operation to expose and define the anatomic anomaly and protect it from injury.