Various kinds of electric currents were examined with regard to their efficacy in the relief of pain when applied transdermally. The most suitable form of current was applied to 39 cases (who had been especially selected in a negative sense) suffering from intractable pain. About half were patients with malignant disease encroaching or causing pressure on nerves or plexuses. The other half consisted of patients suffering from intractable neuralgia totally resistant to all forms of therapy. A diagram of the pulsating direct current is shown. Results were as follows: no effect in nine cases; 5 cases obtained moderate relief of pain for up to 12 hours; the remaining 25 patients reported complete relief of pain already after the first application of current lasting from 12 hours to 3 weeks and--after a series of sessions (3 to 17 treatments)--of up to 12 months. Two of these patients were supplied with a unit for home treatment after their relatives had been trained in the use of the instrument. In these two cases, however, a large number of treatment sessions became necessary. These results warrant continued study of cases of this kind and call for a study of the basic mechanisms possibly underlying these effects. If the present results are confirmed, it is planned to introduce battery-powered miniaturized sets, which patients may use themselves after fixation of electrodes.