The enzyme-linked immunosorbent assay (ELISA) was used to examine sera from twelve Taiwanese children with eosinophilic meningitis suspected to be induced by infection with Angiostrongylus cantonensis. Polystyrene tubes were coated with Angiostrongylus cantonensis antigens (5 micrograms/ml protein) prepared from fourth-stage larvae recovered from the brains of experimentally infected rats. Alkaline phosphatase labelled goat antihuman IgG conjugate was used in a dilution of 1 to 500; sera were diluted 1 to 1000. Positive control sera were from patients with parasitologically confirmed infections; the negative control sera from healthy persons. The ELISA values for sera from suspected cases of angiostrongyliasis ranged from 4.5 to 23.1; the positive control sera, 12.7 to 34.4 and the negative control sera 1.3 and 2.2. The assay shows promise and with the use of more purified antigens, micromethods and automated ELISA readers it should become valuable in the presumptive diagnosis of angiostrongyliasis in endemic areas.