Each of 20 consecutive patients with a history of at least 1 year of intractable chronic cervicobrachial pain was randomly assigned to one of two treatment groups. The pretreatment investigation included at least three diagnostic segmental nerve blocks in each patient. Each patient in Group 1 received a 67 degrees C radiofrequency lesion adjacent to the dorsal root ganglion. The patients in Group II were treated in an identical manner as those in Group I, except that no actual radiofrequency lesion was made. Neither the therapist nor the patients were aware of the treatment group assignment. All patients were questioned about their pain experience 1 week before and 8 weeks after the procedure. The following tests were used in evaluating patient response: Visual Analogue Scale (VAS); McGill Pain Questionnaire, Dutch Language Version (MPQ-DLV); and Multidimensional Pain Inventory, Dutch Language Version (MPI-DLV). These tests showed that 8 weeks after the procedure, there was a significant number of "successful" patients in Group I compared to Group II (P = 0.0027); there was a significant reduction in VAS score (P < 0.01) and also in parameters measured with MPQ-DLV and MPI-DLV in Group I. This study indicates that a 67 degrees C radiofrequency lesion adjacent to the dorsal root ganglion can result in a significant alleviation of pain in chronic cervicobrachial pain.