Adult paratesticular rhabdomyosarcoma (PRMS) with invasion of the retroperitoneum and involvement of the infrarenal aorta and inferior vena cava (IVC) is rare. We describe a 23-year-old male diagnosed with PRMS in 2008, previously treated with right orchiectomy, chemotherapy, and radiation, who presented with new onset of lower back pain. Computed tomography (CT) scan revealed a 4.8 × 4.2 cm mass involving both the infrarenal aorta and the IVC. We resected the tumor en bloc with in situ reconstruction of the aorta utilizing a Dacron graft and the IVC with a bovine pericardium roll graft. His postoperative period was uneventful, and he was discharged on postoperative day 6 in stable condition. At 2-month follow-up, the patient recovered well from the surgery, patent grafts on CT scan with no clinical signs of lower extremity ischemia or edema, and he continues to receive cycles of chemotherapy.