Peridural injections of morphine were given to 180 incurable cancer patients suffering chronic pain. The effectiveness of the said procedure as well as its side-effects were assessed. A relationship between the external respiration parameters, on the one hand, and drug dosage and time postinjection, on the other, was studied. The data obtained point to the effectiveness of the said method and suggest that it be used as a universal procedure for the treatment of intractable pain in incurable patients.