['Single-arm, prospective clinical trial.', 'To evaluate back pain severity, physical function, and quality of life outcomes in highly selected patients with lumbar discogenic pain treated with intradiscal electrothermal therapy (IDET).', 'Degeneration and disruption of the intervertebral disc can be the source of severe low back pain and the associated physical dysfunction. IDET is a minimally invasive treatment option in the continuum of care between conservative nonoperative management and spinal surgery.', 'Using magnetic resonance imaging, pressure-controlled discography, and postdiscogram computed tomography findings, 56 patients with lumbar discogenic pain were identified, underwent IDET treatment and followed for 20.5+/-4.4 months, on average. Outcomes included assessments of back pain severity by visual analog scale, sitting, standing, and walking tolerances, and health-related quality of life using the SF-36.', 'Mean pain severity scores (visual analog scale) improved from 6.1+/-1.8 pretreatment to 2.4+/-2.6 at final follow-up (P=0.0001). Mean tolerance times (minutes) improved from 40.9+/-40.6 to 84.5+/-54.4, 46.8+/-42.9 to 84.4+/-54.2, and 39.2+/-39.6 to 77.9+/-50.8 between baseline and final follow-up for sitting, standing, and walking, respectively (P=0.0001 for all comparisons). Seven of 8 quality of life domains showed significant (P=0.0001 for all comparisons) improvement over baseline. Forty-two patients (75%) were classified as a treatment success by virtue of a >or=2-point improvement in pain severity or a >or=10-point improvement in either the physical functioning or bodily pain domain of the SF-36.'] Does intradiscal electrothermal therapy ( IDET ) provide effective symptom relief in patients with discogenic low back pain?