A generalized allergic reaction or anaphylactic reaction following a fire ant sting may involve the skin, with erythema, pruritus, urticaria, or angioedema; the respiratory tract, with laryngeal edema and bronchospasm; the cardiovascular system, with myocardial depression, hypotension, and shock; and the gastrointestinal system, with nausea, vomiting, and diarrhea. Anaphylactic shock due to a fire ant sting has rarely been reported. We describe a previously healthy 40 year-old man who developed, nausea, vomiting, diaphoresis, dizziness, hypotension, and a generalized skin rash after a single fire ant sting to his right hand. His serum immunoglobulin E (IgE) rose to 420 IU/mL. He responded to antihistamines, dopamine, corticosteroids, and fluid replacement.