STUDY DESIGN: This was a case-control study. OBJECTIVE: The present study aimed to evaluate the significance of circumferential tumor resection around the spinal cord in palliative decompression surgery for patients with metastatic spinal cord compression (MSCC) in the thoracic spine. SUMMARY OF BACKGROUND DATA: Although the benefits of palliative surgery for MSCC are well known, the significance of circumferential tumor resection with cord compression has not yet been clarified. MATERIALS AND METHODS: We retrospectively compared the outcomes of 45 and 34 patients with incomplete paralysis of modified Frankel grade B-D caused by MSCC with anterior cord compression (epidural spinal cord compression grade ≥2) treated at 2 different university hospitals (H1 and H2, respectively). All patients in H1 hospital underwent posterior decompression only, while all patients in H2 hospital underwent full circumferential decompression. We analyzed factors that affect the postoperative ambulatory status. evaluated by the modified Frankel classification. RESULTS: No significant differences were observed in the epidural spinal cord compression grade, spinal instability neoplastic score, new Katagiri score, revised Tokuhashi score, or postoperative survival between patients in H1 and H2 hospitals. A multivariable logistic regression analysis identified preoperative radiotherapy [odds ratio (OR): 0.23, 95% confidential interval (CI): 0.056-0.94] as a negative risk factor and postoperative chemotherapy (OR: 5.9, 95% CI: 1.3-27.0) as a positive risk factor for an improved ambulatory status. Five and 6 patients in H1 and H2 hospitals, respectively, showed deterioration in the ambulatory status. An older age (OR: 1.1, 95% CI: 1.0-1.2) and preoperative radiotherapy (OR: 10.3, 95% CI: 1.9-55.4) were extracted as significant independent risk factors for deterioration in the ambulatory status. Circumferential decompression did not improve the clinical results of patients regardless of the degree of paralysis. CONCLUSIONS: Preoperative radiotherapy interfered with the recovery of paralysis, and postoperative chemotherapy improved the ambulatory status. Clinical outcomes did not significantly differ between total circumferential decompression and posterior decompression, although further validation in a small number of cases is needed, such as patients with Frankel grade D.