BACKGROUNDPalliative care education for health care professionals is a key element in improving access to quality palliative care. The Palliative Care Emphasis Program on Symptom Management and Assessment for Continuous Medical Education (PEACE) was designed to provide educational opportunities for all physicians in Japan. As of 2015, 57,764 physicians had completed it. The objective of this study was to estimate the effects of the program.METHODSThis study was an analysis of 2 nationwide observational studies from 2008 and 2015. We conducted 2 questionnaire surveys for representative samples of physicians. The measurements used were the Palliative Care Knowledge Test (range, 0‐100) and the Palliative Care Difficulties Scale (range, 1‐4). Comparisons were made with the unpaired Student t test and with a multivariate linear regression model using 2 cohorts and a propensity score–matched sample.RESULTSThis study analyzed a total of 48,487 physicians in 2008 and a total of 2720 physicians in 2015. Between 2008 and 2015, physicians' knowledge and difficulties significantly improved on the Palliative Care Knowledge Test with total scores of 68 and 78, respectively (P < .001; effect size, 0.40) and on the Palliative Care Difficulties Scale with total scores of 2.65 and 2.49, respectively (P < .001; effect size, 0.29). Propensity‐score matching resulted in 619 untrained physicians matched to 619 trained physicians, and physicians who trained with the PEACE program had a higher knowledge score (74 vs 86; P < .001; effect size, 0.64) and a lower difficulties score (2.6 vs 2.3; P < .001; effect size, 0.42).CONCLUSIONSPhysicians' knowledge of and difficulties with palliative care improved on a national level. The PEACE program may have contributed to these improvements. Cancer 2018;124:626‐35. © 2017 American Cancer Society.