Background: The Spinal Instability Neoplastic Score (SINS) is used to assess mechanical instability based on radiographic and clinical factors. We conducted this study to evaluate the clinical utility of SINS in surgical decision-making in spinal metastasis and its association with metastatic epidural spinal cord compression (MESCC). Methods: We allocated 285 patients with spinal metastatic disease through a retrospective review. SINS was calculated using good-quality computed tomography. The degree of MESCC was assessed using 0 to 3 grading system. Results: Based on SINS, patients were categorized into stable (35.1%), potentially unstable (52.3%) and unstable (12.6%) groups. In the surgical intervention group, there was 69.5% treated with decompression and instrumented fusion, 17% with decompression alone, 8.5% with percutaneous vertebral augmentation and 5% with instrumented vertebral augmentation. A significantly higher proportion of patients with stable SINS (63.6%) were treated surgically without instrumentation (X2=10.6, P=0.005), whereas instrumentation was utilized in 87.5% of patients with unstable SINS. Grade 3 MESCC occurred in 65.5% of patients with unstable SINS, whereas 71.4% of patients with stable SINS had grade 0 MESCC (X2=42.1, P<0.001). Conclusions: SINS is associated with higher degrees of MESCC and plays an important role in surgical decision-making, facilitating assessment and recognition of spinal instability in need of urgent appropriate surgical interventions.