A case of medullary compression is reported which was found to be due to an epidural lymphoma of the nodular type, which was centrofollicular, with only slight lymphocytic differentiation, and appeared to be isolated. The hour-glass appearance of the tumour suggested, however, that it was not the primary tumour. The short term outcome appeared to be favourable after surgery and radiotherapy but a limited period of chemotherapy is being given. Reports on the frequency of medullary compression during malignant non-Hodgkinson lymphomas vary between 1 and 15% of cases, and many cases have revealed the actual cause, especially in neurosurgical practice. Most authors do not accept the existence of lymphomas primarily located in the epidural space, and feel that they result from metastatic invasion or by contiguity. Prolonged survival can be hoped for after mixed treatment of these tumours, especially in histologically favourable forms.