There are considerable discrepacies between clinical symptoms and imaging diagnosis in the localization of the responsible radiculopathy. The purposes of this study are to analyze the dynamic alteration of contrast filling of the spinal nerve sleeves during positional changes and to determine how the abnormalities of nerve sleeves on lateral bending A-P views correlate with sciatica. The criteria indicating the root abnormality in functional myelography were (1) bad filling of ipsilateral root to sciatica and (2) good filling of contralateral root compared with those in neutral A-P view. Of total 77 patients, 67 had radiculopathy and 10 had no radiculopathy. In 23 (34.3%) of 67 patients with radiculopathy and 6 (60%) of 10 patients with no radiculopathy, their clilnical symptoms well correlated with conventional myelographic findings. However, in 35 (52.2%) of 67 patients with radiculopathy and 6 (60%) of 10 patients with no radiculopathy, their symptoms well correlated with functional myelographic findings. This study suggests that the functional myelography using both lateral bending A-P views can be used as a complementary tool in the evaluation fo the radiculopathy.