Although jellyfish stings are an uncommon medical problem in temperate Australia, significant morbidity can occur, particularly in association with infestations of large numbers of jellyfish in public swimming areas. We report a case of a jellyfish sting-related eye injury, probably caused by the "hair" jellyfish (Cyanea capillata) from southeast Australia. The patient, a 54-year-old man, was stung while swimming without goggles in a jellyfish-infested bay. He experienced severe pain in his right eye, requiring narcotic analgesia, and had decreased visual acuity associated with right-sided facial swelling. Although usually brief and self-limiting, eye injuries after jellyfish stings should be assessed and treated as early as possible to reduce the risk of longer term sequelae. Water safety campaigns should incorporate information on the prevention and early treatment of such stings.