Secondary involvement of inferior vena cava is a common presentation in aggressive solid malignancies, especially arising from kidneys, adrenals, and hepatobiliary system, mostly resulting from local infiltration. Rarely, primary tumors are seen arising from vascular tissue. The Ewing family of tumors commonly arises from bone, but there is a high propensity of these tumors to originate from nonosseous sites of mesenchymal cell origin. We would herewith demonstrate a rare presentation of Ewing sarcoma, seen originating from inferior vena cava, presenting as extensive intravascular tumor thrombosis, evaluated on FDG PET/CT imaging in a 12-year-old girl.