This study analysed the outcome of 35 consecutive patients with intramedullary ependymoma who underwent a radical surgical resection between 1983 and 1996. The median age of patients was 47 years. Tumour location was cervical in 22 patients, cerviothoracic in eight and thoraco lumber in five. The proliferative activity of 24 spinal and 14 intracranial ependymomas were determined by MIB-1 immunolabelling. Total removal of tumour was achieved in 26 patients and subtotal removal was performed in nine patients of whom six received postsurgical radiation therapy. Twenty-nine patients out of 35 could be followed over 3 years (follow-up periods: 168-36 months: mean 70). Moreover many patients could be followed over 4 years. In 27 of those 29 patients, the neurological symptom was stabilized or improved. The proliferation indices of spinal ependymomas were significantly lower than those of intracranial ependymomas. Tumour regrowth occurred only in a young patient 29 months after a subtotal removal of the tumour which was not treated with irradiation and showed a high proliferation index on the second operation.