Inferior vena cava agenesis is a rare congenital, often asymptomatic vascular anomaly, usually detected accidentally during medical imaging or interventions. In the literature, an association between inferior vena cava malformations and congenital defects of other organs (anomalies of the heart, spleen, kidneys, bowels) has been reported. This results from the concurrent development of these organs in the embryological process. We describe the agenesis of the lower part of the inferior vena cava coexisting with nephropathy, hypertension, unicornuate uterus, lipoma of the lumbar spine, spina bifida, increased activity of factor VIII and von Willebrand factor in a 12-year-old girl. This combination of defects appears to be unique in the medical literature. Exploring and understanding the nature of the link between these conditions could be crucial for avoiding unnecessary surgical interventions, malpractices, and diagnostic errors.