Background. Oncologists play a significant role in cancer care throughout the cancer trajectory and have traditionally emphasized underuse of procedures/treatments with well-established effectiveness as the source of poor care quality with little attention to overusing end-of-life (EOL) care. The purpose of this populationbased study was to compare the quality of EOL care between medical oncologists and other physician specialists. Methods. This retrospective cohort study compared indicators of poor quality EOL care by examining administrative data for 204,850 Taiwanese cancer decedents in 2001-2006. Results. Taiwanese cancer patients whose primary physician was a medical oncologist were significantly more likely than patients of other physician specialists to receive chemotherapy and to spend >14 days in a hospital in the last month of life. However, they were significantly less likely than patients of other physician specialists to visit the emergency room (ER) more than once and to use intensive care unit (ICU) care, cardiopulmonary resuscitation (CPR), intubation, and mechanical ventilation in the last month of life. Conclusion. The quality of EOL cancer care in Taiwan varied significantly by physician specialty. Cancer decedents cared for by medical oncologists were more likely to receive chemotherapy and prolonged hospitalization but less likely to have multiple ER visits, ICU care, or undergo CPR, intubation, or mechanical ventilation in the last month of life than patients of other physician specialists.