The authors make a literature review about the meningeal envolvement in MM and verified that the presence of myeloma cells in the CSF is rare. They report a case of cranial MM in which the atypical plasma cells (plasmoblasts) were present in CSF. The CSF examination was the principal finding to the diagnosis of this case; it was comfirmed by IgG monoclonal "M" gamophaty present in serum, CSF and urine obtained through proteic electrophoresis profile and by necropsy that revelled mielomatous proliferation in skull base with subarachnoidal space infiltration.