The authors report a case of a 16-year-old girl who presented with a 1-week history of progressive low-back pain, buttock paresthesias, and bilateral lower extremity pain and weakness. Magnetic resonance (MR) imaging and MR venography studies of her lumbar spine revealed engorgement of the epidural venous plexus and mild compression of the cauda equina. A lower extremity and pelvic venogram revealed occlusive thrombosis of the femoral and iliac veins as well as of the inferior vena cava (IVC). The patient required an IVC thrombectomy due to progressive symptoms, after which she improved and returned to baseline status in 1 week. Imaging studies afterwards showed resolution of the venous engorgement and decompression of the cauda equina. This is the second published report of an association between IVC thrombosis and cauda equina syndrome.