A 57-year-old white female, operated on for a prolapsed disc six years ago, presented with low back pain. Initially, she was thought to be suffering from the same disc problem, and was treated accordingly. However, her condition worsened. A myelogram disclosed a complete block of the subarachnoid space from levels T11 to L2. Laminectomy and decompression were performed, revealing tumor in the extradural space. Histological examination disclosed a primary, poorly differentiated lymphocytic lymphoma of the spinal cord. Both primary and metastatic non-Hodgkin's lymphoma of the spinal cord are extremely rare. Mullins et al described only five instances of cord compression in a study of 529 cases of non-Hodgkin's lymphoma. The diagnosis is generally not suspected until laminectomy.