One hundred and twenty-five patients with eosinophilic meningitis or meningoencephalitis were studied in southern Taiwan in 1968 and 1969. The majority of patients had mild to moderate disease, but several had severe manifestations. Four patients died and three others had severe permanent sequelae such as blindness. Young adult Angiostrongylus cantonensis were recovered from nine patients, at autopsy in one, and from the cerebrospinal fluid of eight who survived. The clinical manifestations of cases of proven etiology were similar to those of cases from which parasites were not recovered and it is believed that the latter also were the result of infection with A. cantonensis.