A 52-year-old woman underwent en bloc resection of a recurrent ovarian cancer metastasis invading the right external iliac vein, followed by anatomical venous reconstruction using a bovine pericardial patch (XenoSure). The reconstructed vein remained patent until 6 months postoperatively but became occluded at 11 months due to recurrent tumor compression. Worsening right-leg edema developed after occlusion. This case suggests both the potential clinical value and limitations of anatomical iliac vein reconstruction using a biological conduit.