Education programs for certified palliative care nurses who promote advance care planning (ACP) for cancer patients are important, but not currently available in Japan. This study aimed to develop an educational program of ACP for certified palliative care nurses in Japan and evaluate its effectiveness. A program consisting of four modules was implemented for 60 certified palliative care nurses in the Kyushu, Chugoku, and Shikoku regions. Participants attended one training session, and 39 responded to a survey on changes in ACP practice and difficulties with cancer nursing 3 months after the intervention. The Wilcoxon signed-rank test was performed to compare data before and after the intervention. The results obtained showed an increase in dialogue on ACP among patients/families and healthcare professionals (mean before the intervention = 24.49, mean after the intervention = 27.59, p = 0.045), and a significant decrease in the sense of difficulty with knowledge of and skills for ACP (mean before the intervention = 4.85, mean after the intervention = 4.30, p = 0.001). More than 90% of the participants gave positive comments on the evaluation items such as understanding and satisfaction with the educational program and appropriateness of the contents. After attending the training program, participants’ sense of difficulty with their knowledge of and skills for ACP decreased, and their practice of ACP increased. This program may promote the practice of ACP for cancer patients in the future.