Although living-donor liver transplantation (LDLT) of right lobe graft is becoming a popular option for adult patients, management of venous outflow remains controversial. We report a successful extended-right lobe liver transplantation using a recipient's left portal vein as a graft from the middle hepatic vein. Preoperative three-dimensional computed tomography (3D-CT) of the donor revealed a small right hepatic vein (RHV) without inferior RHV and a large middle hepatic vein (MHV) draining segments 5 and 8. During the donor operation, right lobe graft was harvested with the MHV, preserving the drainage vein from segment 4. The donor recovered uneventfully except for mild transient hyperbilirubinemia. The recipient's condition rapidly improved, and was discharged from hospital 49 days postoperation. A 3D-CT after LDLT also clearly revealed successful vascular anastomosis. Preoperative and postoperative 3D-CT was useful for determination of the vascular anatomy and the decision about the line of transection in the donor hepatectomy, as well as for evaluation of the vascular anastomoses after transplantation.