To investigate the effect clinical path of cancer pain treatments for opioid naive patients has on physician practice, a prepost quasi-experimental study was performed. The primary outcome measure was the percentage of patients who received 'recommended pain treatments' during the study periods. We determined the treatment to be the treatment of choice, if the physician 1) ordered a rescue dose, 2) prescribed a laxative, and 3) prescribed antiemetics when starting opioids. The secondary outcome measure was the number of newly consulted patients for our palliative care team. The end-points were measured before and after disseminating the clinical path. The rate of patients receiving recommended pain treatments significantly increased after disseminating the clinical path(p=0.03): 17%(33/18)to 61%(19/31). Patients who received a rescue order, laxative, or antiemetic when starting opioids were: 44% vs. 68%, 77% vs. 90%, and 66% vs. 77%, respectively. The number of patients newly consulting the palliative care team was increased(21 cases to 42 cases/4 month). In conclusion, the clinical path of cancer pain treatments is useful for improving the physician's practice when starting opioids for cancer pain, and might contribute to enhancing palliative care team availability.