INTRACEREBROVENTRICULAR MORPHINE ANALGESIC for the treatment of cancer pain was administered, using implanted access ports, in 82 patients from 1984 to January 1994. All of the patients who were selected for treatment were no longer responsive and had developed drug side effects to oral or parenteral opiates in varying doses (60–400 mg/d). The mean follow-up was 66 days (range, 12–443 d) for this series of 82 patients. The effective control of pain was achieved in nearly all of the patients, with only two failures. During the treatment, the daily morphine doses were moderately increased. The initial doses of morphine were a mean of 0.30 mg (range, 0.10–2 mg), and the final doses were a mean of 2.5 mg (range, 0.10–60 mg). The results show that the ratio of the terminal dose to the initial dose increased more rapidly for patients who had a follow-up of over 60 days. However, the increase seems to have been because of the progress of the disease rather than because of drug tolerance.