We investigated ant sting related fatalities in Australia over the period 1980-1999. Data was obtained from the Australian Bureau of Statistics and state coronial authorities. Six ant sting-related fatalities were identified, five in Tasmania and one in New South Wales. All were males aged between 40 and 80-years-of-age and most (5/6) had prior histories of jumper or bull ant (Myrmecia spp.) venom allergy. However, none of the deceased carried injectable adrenaline and most died within 20 min of a single sting. Significant cardiopulmonary co-morbidities were identified in all cases and, in addition, moderate-severe laryngeal oedema and coronary atherosclerosis was observed in most (4/6) cases at autopsy. Where ascertained, Myrmecia ant venom specific immunoglobulin E antibodies levels were always elevated and fell into two distinct patterns of immunoreactivity. Adult Tasmanian males with a prior history of ant venom allergy and cardiopulmonary co-morbidities are therefore at highest risk of a fatal outcome from ant stings. Deaths may be avoided by the early recognition of anaphylaxis and self-treatment with adrenaline as well as by the development of purified Myrmecia ant venom immunotherapy.