BACKGROUND: Intramedullary cavernous malformations (CMs) are rare lesions with unclear natural history. OBJECTIVE: To compare the functional outcomes of spinal CMs managed surgically and conservatively. METHODS: We performed a retrospective study of patients diagnosed with intramedullary CMs seen at our institution from 2006 to 2013. Functional outcomes of patients were assessed by treatment modality with the Modified McCormick Scale and Karnofsky Performance Status. RESULTS: We identified a total of 85 study-eligible patients; 51 (60.0%) were male. Mean age of patients was 40.5 years. Fifty-eight patients underwent microsurgical removal, and 27 patients underwent conservative management. All patients except 1 harbored a single symptomatic intramedullary CM. Mean follow-up time was 42.8 months. For the surgical group (n = 58), 51 CMs were completely resected. During the follow-up period, 40 patients (69.0%) within the surgical group had improvement in neurological state, 16 patients (27.6%) remained unchanged, and 2 patients (3.4%) experienced deteriorated functional status. In the conservative group, 4 patients (14.8%) had improvement of their symptoms, 19 patients (70.4%) remained in baseline, and 4 patients (14.8%) deteriorated. No significant statistical difference was observed in follow-up Karnofsky Performance Status assessment (odds ratio = 0.89; 95% confidence interval = 0.73-1.08; P = .15) or Modified McCormick Scale assessment (odds ratio = 0.90; 95% confidence interval = 0.74-1.10; P = .30) after adjustment for preoperative lesion size and location. Annual hemorrhagic risk was 3.9% in conservatively managed patients. In contrast, no patients experienced subsequent hemorrhages after surgical resection. CONCLUSION: Surgical resection of intramedullary CMs eliminates the risk of subsequent hemorrhagic and may achieve satisfactory outcome when patients are carefully selected. Although conservative management is recommended in patients at high surgical risk, they should be closely monitored because of persistent hemorrhagic risk.