Between January 1984 and December 1990, 65 intramedullary spinal cord tumors were diagnosed and operated on. In this series, all patients underwent magnetic resonance imaging investigations and were operated on with the Cavitron ultrasonic surgical aspirator whenever necessary. Major surgical difficulties have been found in patients previously treated by radiotherapy with or without biopsy. We found magnetic resonance imaging to be a highly sensitive imaging procedure and the method of choice for visualizing tumors within the spinal cord. Nevertheless, accurate diagnosis may only be suggested by magnetic resonance imaging, rather than made definitively. Surgery is necessary in every case in order to obtain a definite diagnosis. Radical surgery can be performed when a plane exists between the tumor and the normal spinal cord: biopsy or debulking with the Cavitron ultrasonic surgical aspirator should be performed when the tumor is infiltrative. We have performed 33 so-called total resections, 22 partial resections, and 10 biopsies, among which 5 were performed on lipomas. Surgical results were assessed at 3 months after surgery, showing 35 improvements (53%), 24 stabilizations (37%), and 6 deteriorations (10%).