BACKGROUND Iliac vein injuries usually require surgical intervention due to their high mortality rates. Although conservative management may be applicable in some cases of blunt trauma, the suitability of this approach for treating penetrating injuries remains underexplored. CASE REPORT A 51-year-old man sustained a common iliac vein injury following rectal impalement in a collapsing chair. After initial resuscitation, he underwent an emergency laparotomy, which revealed no ascites or blood in the abdominal cavity. Given the stability of the hematoma, the decision was made to avoid incising the retroperitoneum, thus maintaining the tamponade effect. A double-barrel stoma was fashioned in the transverse colon to address the rectal damage. The patient's postoperative course was initially uneventful, with no confirmed hematoma expansion on the second computed tomography scan. The patient was discharged on postoperative day 11 following a consistent decrease in D-dimer levels. However, 4 days after discharge, he presented with edema in the right lower extremity. He was diagnosed with deep vein thrombosis (DVT) and pulmonary embolism (PE), which were managed with intravenous heparin and direct oral anticoagulant (DOAC). The patient continued follow-up visits without further complications. CONCLUSIONS This report presents the first documented case of conservative management of an iliac vein injury resulting from an impalement wound. It highlights the potential of a nonsurgical approach in stable patients and underscores the importance of considering postoperative prophylactic anticoagulation therapy to prevent DVT and PE.