Recent reports have attempted to compare the relative value of discography and MRI in the evaluation of lumbar degenerative disc disease. None has compared the accuracy of the two techniques in regard to the detection of disc herniation specifically, and none has offered surgical correlation. In this prospective study, both techniques were used to evaluate 264 disc levels in 90 patients with incapacitating low back pain or radicular pain. The results showed an 86% agreement level both between tests and between the orthopaedist and radiologist on each test. Surgical findings agreed with diagnostic studies at 63 of 76 levels in 57 patients who underwent operative treatment. An analysis of the relative sensitivity and specificity of each test in the diagnosis of degeneration and herniation revealed that the greater sensitivity of MRI in the detection of herniation was the only statistically significant difference (p < 0.05).