The reported results of treatment of intramedullary spinal cord tumors (IMSCT) are difficult to interpret because of heterogeneous management strategies, small numbers of patients, and short periods of follow-up. In 1985 we published the early results of operative treatment of 29 patients with IMSCT and were cautiously optimistic that aggressive operative management would have a salutary effect on long-term outcome. In this report, the most recent clinical status of these 29 original patients is reviewed along with that of 22 additional ones, to assess the intermediate and long-term results of treatment of IMSCT in 51 patients who underwent microsurgical resection between 1981 and 1987. Of these 51 patients, 24 had ependymomas, 18 had astrocytomas, and the remainder had a variety of less common lesions. Thirty-seven patients survive and have been followed for periods up to 72 months (mean 38 months). The neurological conditions of 21 patients are improved or have stabilized following operation. The conditions of 16 patients are worse postoperatively: 11 from operation and 5 from progression of disease. Eight patients are neurologically intact, 7 walk independently but abnormally, 9 ambulate with the aid of a cane or walker, and the remaining 13 are not ambulatory. Twelve of 18 patients with astrocytomas and 2 of 24 patients with ependymomas have died after a mean survival of 10 months from operation. Patients with ependymomas who had gross total resection have fared the best, with no deaths or recurrences, but no relationship could be discerned between the extent of resection and outcome in patients with astrocytomas.(ABSTRACT TRUNCATED AT 250 WORDS)