The aim of this randomized open-label prospective study was to evaluate the analgesic activity of buprenorphine in a transdermal formulation for cancer chronic pain control versus sustained-release morphine, in all cases combined with oral tramadol. A transdermal system with 35 microg/h buprenorphine was applied to the first group of patients (BT); the second group received 60 mg/day of sustained-release morphine (MT). In both groups oral tramadol was administered to a maximum of 200 mg daily, in case of need. The administration of transdermal buprenorphine versus morphine resulted in significant differences in the physical pain (P = 0.01), mental health (P = 0.03) and vitality (P = 0.001). These data indicated that the BT group showed an improvement of pain and a positive effect on the quality life.