Nematodes suspected to be Angiostrongylus cantonensis were first identified in the cerebrospinal fluid of a patient with eosinophilic meningitis by Nomura and Lim in Taiwan in 1944. They called the parasite Haemostrongylus ratti, and noted that raw food eaten by the patient may have been contaminated by rats. Their paper, however, was not translated from the original Japanese into English until just after the parasite had been recognized in 1964, so their discovery was not widely recognized.

In 1955, Mackerass and Sanders identified the life cycle of the worm in rats, defining snails and slugs as the intermediate host and noting the path of transmission through the blood, brain, and lungs in rats.