Objective: To introduce a successful experience of tapering high-dose opioids using spinal analgesia. Case: A 53-year-old man suffering from buttock-pain due to sacral metastasis of rectal cancer, was referred to our hospital for specialized cancer pain treatment and opioid reduction. At the time of admission, he was taking 5040 mg/day of oral morphine equivalent dose of opioids and NRS was still 10/10. Although the dosage was too high, an illicit transactions, diversion or psychological dependence were ruled out. Exacerbation of pain and tolerance formation due to the rapid increase of opioid dose seemed to be a vital factor. After admission, the high-dose opioid was gradually reduced while epidural and intrathecal analgesia were introduced. After 30 days of adjustment, the dose of systemic opioid was finally reduced to 120 mg/day (oral morphine equivalent) with 24 mg/day of intrathecal morphine at the time of transfer to his primary hospital. Conclusion: Cancer pain can result in high-dose opioids administration. Specialized pain treatment may be useful in weaning patients from high-dose opioids, but early concomitant use is recommended to avoid becoming high-dose opioid.