Introduction: This is the first report about an outpatient who was successfully switched from oxycodone to methadone without any serious problems in Japan. Case report: A man in his 60s who was diagnosed as advanced pancreatic cancer with multiple bone and liver metastases. Since he complained severe cancer pain in spite of taking oxycodone 40mg/day, he was referred to the palliative care team. After discussion about switching from oxycodone to methadone in the palliative care team and obtaining informed consent from him, it was decided to prescribe methadone in the outpatient setting. During induction of methadone, a palliative care certified nurse (CN) played important roles about explanation of futures, pharmacodynamics, pharmacokinetics and side effects, education how to take, monitoring of analgesic and side effects and supports to patient anxieties about methadone. His dose titration of methadone was completed for 15 days, and his adequate dose was decided as 20 mg/day finally. After titration of methadone, pain relief could be achieved. Conclusion: Although methadone has a possibility to improve management of cancer pain, it has some serious problems, such as respiratory depression, QT interval prolongation and others due to unsuitable use. Therefore, patients with prescription of methadone must be educated, monitored and supported by special medical staff with much experiences and knowledge about cancer pain, opioid therapy and methadone. CNs may play important role to keep safety and resolve patients and families’ anxieties for prescription of methadone.