Discography appears to be the only means to give radiological, strictly anatomical and clear visual data on the nucleus of a disc. It is a comparatively simple and technically easy technique as long as one has the right tools and personnel. While it is disagreeable for the patient, it is not dangerous if strict asepsis can be applied. Discography gives an uncomplicated and unequivocal interpretation with sufficiently precise discometric and sensory signs which enable us to identify the lesion reliably. Tolerance and harmlessness of the technique are by now established. The indications refer to disc pathology and are indispensable before any arthrodesis carried out for pain in the lumbar spine or spondylolisthesis. These indications are now being extended to all problems of reports or difficult diagnosis of vertebral pathology. Discography also has a special and essential place with sciatica, particularly when radiculography is negative.