Object. The authors conducted a study to assess the clinical pattern, radiological features, therapeutic strategies, and long-term outcomes in patients with intramedullary spinal cord cavernomas (ISCCs) based on a large case series. Methods. This retrospective study identified 96 patients (60 males, 36 females) surgically (81 cases) or conservatively (15 cases) treated for ISCCs between May 1993 and November 2007. Each diagnosis was based on MR imaging and spinal angiography evidence. For all surgically treated patients, the diagnosis was verified pathologically. The neurological outcomes pre- and postoperatively, as well as long-term follow-up, were assessed using the Aminoff-Logue Disability Scale. Results. The mean age at the onset of symptoms was 34.5 years (range 9-80 years). Of the lesions, 68 (71%) were located in the thoracic spine, 25 (26%) in the cervical spine, and only 3 (3%) in the lumbar spine. The median symptom duration was 19.7 months. The clinical behavior of the lesion was a slow progression in 73 cases and an acute decline in 23 cases. Long-term follow-up data (mean 45.8 months, range 10-183 months) were available for 75 patients (64 surgical cases and 11 conservative cases). In the surgical group, a complete resection was achieved in 60 patients, and incomplete resection was detected in 4 patients after operation. At the end of the follow-up period in the operative group, 23 patients (36%) improved, 35 (55%) remained unchanged, and 6 (9%) worsened. In the nonoperative group, 5 patients improved, 6 patients remained unchanged, and none worsened. Conclusions. For differential diagnosis, spinal angiography was necessary in some cases. For most symptomatic lesions, complete microsurgical resection of the symptomatic ISCC is safe and prevents rebleeding and further neurological deterioration. However, in patients whose lesions were small and located ventrally in the spinal cord, one can also opt for a rigorous follow-up, considering the high surgical risk. (DOI: 10.3171/2011.5.SPINE10735)