Neurologic manifestations are not unusual in multiple myeloma. Conversely meningeal and cerebral involvement have been very rarely reported. We report here on three patients with multiple myeloma and meningeal or cerebral involvement (two of them with autopsy study): one case of cerebellar involvement associated with secondary plasma cell leukemia and two cases of meningeal involvement. We reviewed the characteristics of 20 cases of meningeal involvement with demonstration of plasma cells at cerebrospinal fluid analysis (18 previously reported cases and our two patients). Meningeal involvement occurs in patients with initially stage III multiple myeloma in 85% of cases and is associated with the occurrence of plasma cell leukemia in 20% of cases. The most frequent neurologic signs are: confusion (60%), altered consciousness (25%), gait disorder (25%), cranial nerve palsy (25%). Meningismus is rarely present. Diagnosis is based on cerebrospinal fluid analysis after lumbar puncture which should be made after cranial magnetic resonance imaging. The diagnosis of intra-cranial haemorrhage and infectious meningitis have to be cautiously ruled out. Despite treatments (systemic and/or intrathecal chemotherapy, radiation therapy), prognosis is very poor: mean time of survival after the occurrence of neurologic signs is about 2 months.