Inferior vena cava (IVC) reconstruction is a complex procedure that, in selected cases, may be the only viable option for achieving complete oncologic resection. One such technique, the use of a peritoneal patch (PP) for IVC reconstruction, is beneficial but rarely reported. In this report, we present a successful case of IVC reconstruction using a PP during the surgical treatment of intrahepatic cholangiocarcinoma. The patient, a 60-year-old female, had an 80 × 77 × 72 mm mass located in segments I, IV, VII, and VIII, involving the IVC. After neoadjuvant chemotherapy and right liver deprivation, she underwent right hepatectomy combined with caudate lobe resection. During surgery, the anterior wall of the IVC was reconstructed using a PP, and the left portal vein was reconstructed with an end-to-end anastomosis. The total operative time was 570 minutes, with no intraoperative complications. The patient was hospitalized for 27 days, including five days in the intensive care unit. Postoperatively, she developed a Clavien–Dindo grade IIIb complication, consisting of gastroparesis, an abdominal collection with a low-output biliary fistula, pleural effusion requiring surgical drainage, and sepsis, which was successfully treated with antibiotics. At 40 months after surgery, the patient remains alive, with no evidence of tumor recurrence and a good quality of life. This case demonstrates that IVC reconstruction using a PP is a feasible alternative for achieving complete oncologic resection. Despite a high but manageable rate of postoperative morbidity, this approach enabled complete tumor resection and resulted in long-term survival.