Treatment of patients with metastatic disease of the spine continues to be a challenging problem. Advances in imaging studies and surgical techniques have improved patient outcomes with operative intervention. However, the lack of a validated set of criteria to determine spinal instability makes patient selection for surgical intervention difficult. Multiple classification systems that assist surgeons in determining appropriate operative candidates have been proposed. We will review current information on the evaluation and treatment of metastatic disease of the spine and discuss classification systems that assist in determining appropriate operative candidates.