Angiostrongyliasis, caused by Angiostrongylus cantonensis, is endemic in northeastern Thailand and southern and eastern Taiwan and is also reported throughout the world. Humans get infected by eating raw freshwater snails or other paratenic hosts. The three main clinical forms of angiostrongyliasis are: eosinophilic meningitis (EoM), eosinophilic encephalitis (EoE) and ocular angiostrongyliasis. EoM, the most common form, causes acute severe headache, and corticosteroid is the cornerstone treatment. EoE is rare but fatal and has no effective treatment. The clinical presentations are coma and cerebrospinal fluid eosinophils without any other causes of the deterioration of consciousness, such as infection or metabolic derangements. Ocular angiostrongyliasis is very rare and causes a permanent visual impairment and a wide range of ocular inflammation, depending on the worm's route. It can occur with or without EoM. An identification of a living worm, usually a single worm in any part of an eye, is an important diagnostic clue. The treatment options are surgical removal or laser therapy. Corticosteroids may be necessary in the case of coexistence of EoM or other ocular inflammations such as retinitis or optic neuritis. The visual outcome is poor and depends on the initial visual acuity.