Two hundred fifty patients with low-back pain who underwent lumbar discography followed by computed tomography (CT) are the subject of this prospective study. In 93% of the patients, these combined imaging techniques provided additional useful diagnostic information that affected patient management and the selection of treatment alternatives. Lumbar discography followed by CT proved valuable in determining the significance of equivocal or multiple level abnormalities, determining the type of disc herniation, defining surgical options, and evaluating the previously operated spine. In 94% of patients who had surgery, CT-discography correctly predicted the type of disc herniation as protruded, extruded, sequestrated, or internally disrupted. Computed tomography-discography may be more sensitive that magnetic resonance imaging (MRI) in the early stages of disc degeneration because 18 of 177 discs with a normal T2-weighted image were discographically abnormal and the CT-discogram revealed annular tears or radial fissuring. The radiographic morphology of the normal herniated and degenerative lumbar discs shown by CT-discography gives unique insight into the pathogenesis of disc degeneration. The complications that followed the 750 discograms were one case of urticaria and one disc space infection. Even with the availability of high resolution CT and MRI, lumbar discography remains the only pain provocation challenge to the lumbar disc.