Donors positive for hepatitis B core antibody (HBcAb) are an important source of organs in hepatitis B virus (HBV) endemic areas despite the risk of occult infection. We analyzed the long-term outcomes of hepatitis B immunoglobulin in de novo HBV prevention following liver transplantation (LT) using HBcAb-positive grafts. The prospectively collected data from 2,201 recipients at Seoul National University Hospital (SNUH) and Seoul National University Boramae Medical Center between 1988 and 2018 were retrospectively reviewed. A total of 1,458 patients were enrolled. Of the 1,458, 478 (32.8%) grafts were core-positive, 152 (10.4%) of which belonged to HBV surface antigen-negative recipients. During the anhepatic phase, hepatitis B immunoglobulin 4,000 IU was administered intravenously and daily until postoperative day 3. The 152 patients with hepatitis B surface antigen-negative received HBcAb-positive graft. De novo HBV developed in 21 (13.8%) of these recipients. De novo HBV occurred in 1, 11, 0, and 9 of the 4 HBcAb- and hepatitis b surface antibody (anti-HB)-negative, 49 HBcAb-negative and anti-HB-positive, 1 HBcAb-positive and anti-HB-negative, and 98 HBcAb- and anti-HB-positive recipients, respectively. Patients with higher Model for End-stage Liver Disease (MELD) score (23.8±8.7 vs. 19.5±9.2) or HBcAb-negative recipients (22.6% vs. 9.1%) had a higher risk of de novo infection. The median follow-up and serum HBV surface antigen-positivity detection time was 69 and 18 months, respectively. The median HBV surface antibody titer was 65.0 IU/L at de novo infection. Nineteen patients of 21 were treated with nucleoside analogs (NAs), and seven of 19 achieved seroconversion. No patient died of de novo HBV infection. With close monitoring of viral serum markers and appropriate initiation of NAs, de novo HBV infection can be prevented and treated appropriately with the hepatitis B immunoglobulin monoprophylaxis protocol.