The growing incidence of cancer pathology all over the world implies not only problems of prevention and cure, but also of pain control. Pain appears in more than 50% of cancer patients, mainly because analgesic opioids are not available or adequately administered. For this reason, the World Health Organization (WHO) has created a Collaborating Centre for Cancer Pain Relief at the Division of Pain Therapy of the National Cancer Institute, Milan. Experts in pain therapy have drafted guidelines on the sequential use of analgesic drugs by identifying three steps: non-narcotics, weak narcotics, narcotics, all in association with adjuvant drugs. After a positive pilot trial, field testing will be conducted in developed and developing countries. The first step of the analgesic ladder is represented by the use of non-narcotics; the adequate use of these substances in advanced cancer patients does not exceed 6 months of treatment. Treatment is then either discontinued or changed to a following step because of side-effects (40%) or inefficacy (44%). The reduction in the use of non-narcotics corresponds to a successive increase in the use of opioids, particularly direct agonists. Through an adequate use of the analgesic ladder, pain can be relieved in the great majority of cancer patients.