SummaryFive cases of bismuth subnitrate encephalopathy are reported. One of them had a prolonged evolution.The clinical picture consists of a confusional syndrome with myoclonus and gait disturbances, to which dysarthria and convulsive seizures may be added. Psychic sequelae and memory deficits may persist for several months.The electroencephalographic alterations are generally moderate and not characteristic.The dosage of bismuth levels in the blood and in the cerebrospinal fluid is an essential diagnostic element, though the blood level of bismuth only partially corresponds to the severity of the clinical signs. Also there is no quantitative relationship between the level of bismuth in the blood and in the cerebrospinal fluid.The treatment of the bismuth encephalopathy is based upon the complete withdrawal of the bismuth ingestion. Enemas may also be useful.In suspected cases, an immediate measurement of bismuth blood levels should be ordered.