OBJECTIVE Reading this article will reinforce the reader's knowledge of the taxonomy, origin, and distribution of fire ants and will increase his ability to diagnose and manage reactions caused by the two imported species, Solenopsis invicta and richteri. This review will also enhance the reader's knowledge of the available diagnostic methods and therapeutic measures, including the role of fire ant venom versus whole body extract in the management of fire ant allergy. METHODS Information for this review was obtained primarily from abstracts and articles written by investigators recognized for their expertise in fire ant venom research. METHODS References were selected based on their clinical applicability and relevance to the epidemiology and pathophysiology of imported fire ant hypersensitivity. CONCLUSIONS The imported fire ant represents a significant health hazard for persons living in fire ant endemic areas in the southern United States. Sting reactions range from local pustules and large, late-phase responses to life-threatening anaphylaxis. Fire ant allergen-specific immunotherapy can reduce the risk of subsequent systemic reactions. Four important Sol i venom allergens have been isolated and characterized. Clinical studies have been designed to compare the safety and efficacy of fire ant venom with whole body extract for diagnosis and treatment of fire ant allergy.