STUDY DESIGN: A case of a patient in whom vertebral osteonecrosis developed after intradiscal electrothermal therapy is reported. OBJECTIVE: To illustrate a potential complication of intradiscal electrothermal therapy and potential strategies to avoid it. SUMMARY OF BACKGROUND DATA: Thermal energy delivered in a controlled fashion directly to the annular wall and disc nucleus has been developed as an alternative to surgical methods for treating internal disc disruption. Although 2-year follow-up data are available, few complications and no vertebral body injury have been reported. METHODS: After intradiscal electrothermal therapy, a patient exhibited MRI changes consistent with osteonecrosis in the adjacent vertebral body. The clinical and radiologic findings are presented, along with a review of the pertinent literature. RESULTS: The magnetic resonance images, the temporal relation of intradiscal therapy, and the patient's clinical symptoms are consistent with focal osteonecrosis of the vertebral body. CONCLUSIONS: This case study highlights a potential complication of intradiscal electrothermal therapy. Catheter placement may expose cortical and cancellous bone to temperatures well within the range reported to induce necrosis. In addition, focal disruption of the endplate may prove to be a relative contraindication for intradiscal electrothermal therapy.