In 114 patients with systemic malignant gammopathies followed during a 10-year period in the hematology clinic of the Rambam Medical Center, 23 episodes of CNS involvement were recorded. 19 cases with spinal cord compression and 4 cases of intracranial plasmacytomas. Early diagnosis followed by prompt laminectomy and subsequent radiotherapy resulted in complete recovery in 50% and partial improvement in 30% of the patients with spinal cord involvement. In good responders. overall survival was not affected by the neurological complication. In the 4 patients with intracranial involvement, external plasmacytomas of the skull preceded the neurological symptoms. 3 of them were diagnosed late, which led to delay and failure of accurate treatment. Only 1 patient was immediately operated and continued to be well for the past 2 years.