Dicroceliasis is an unusual zoonotic trematode infection caused by the lancet liver fluke, Dicrocoelium dendriticum. Grazing herbivores (usually sheep or cattle) are the definitive hosts. The life cycle proceeds through two intermediate hosts: the land snail and the field ant. Human infection is acquired by consuming the field ant. This case report describes a human immunodeficiency virus-seropositive patient who presumably acquired this parasite from bottled water contaminated with ants. A brief discussion of the parasitology, pathology, clinical findings and treatment is presented.