This paper reports on the experience gained using World Health Organization Guidelines for cancer pain relief over a 10-year period in an anaesthesiology-based pain service associated with a palliative care programme. The course of treatment of 2118 patients was assessed prospectively over a period of 140,478 treatment days. Non-opioid analgesics (WHO step I) were used on 11%, weak opioids (WHO step II) on 31% and strong opioids (WHO step III) on 49% of treatment days. Administration was via the enteral route on 82% and parenterally on 9% of treatment days. On the remaining days, either spinally applied opioids (2%) or other treatments (6%) were utilised. Fifty-six percent of the patients were treated with morphine. Morphine dose escalation was observed in about one-half of the patients being cared for until death, whereas the other half had stable or decreasing doses over the course of treatment. Co-analgesics were administered on 37% of days, most often antidepressants (15%), anticonvulsants (13%) and corticosteroids (13%). Adjuvants to treat symptoms other than pain were prescribed on 79% of days, most commonly laxatives (42%), histamine-2-receptor antagonists (39%) and antiemetics (35%). In addition, palliative antineoplastic treatment was performed in 42%, nerve blocks in 8%, physiotherapy in 5%, psychotherapy in 3% and TENS in 3% of patients. A highly significant pain reduction was achieved within the 1st week of treatment (P < 0.001). Over the whole treatment period, good pain relief was reported in 76%, satisfactory efficacy in 12% and inadequate efficacy in 12% of patients. In the final days of life, 84% rated their pain as moderate or less, while 10% were unable to give a rating. Analgesics remained constantly effective in all 3 steps of the WHO ladder. Other clinical symptoms were likewise significantly reduced at 1 week after initial assessment, with the exception of neuropsychiatric symptoms. During the course of treatment, the latter were the major symptoms on 23% of days, followed by nausea (23%), constipation (23%) and anorexia (20%). Our results emphasise once again the marked efficacy and low rate of complications associated with oral and parenteral analgesic therapy as the mainstay of pain treatment in the palliative care of patients with advanced cancer. Wide dissemination of WHO guidelines among doctors and healthcare workers is thus necessary to effect a clear improvement in the treatment of the many patients suffering from cancer pain in the clinical and home setting.