Food anaphylaxis is now the leading known cause of anaphylactic reactions treated in emergency departments in the United States. It is estimated that there are 30 000 anaphylactic reactions to foods treated in emergency departments and 150 to 200 deaths each year. Peanuts, tree nuts, fish, and shellfish account for most severe food anaphylactic reactions. Although clearly a form of immunoglobulin E-mediated hypersensitivity, the mechanistic details responsible for symptoms of food-induced anaphylaxis are not completely understood, and in some cases, symptoms are not seen unless the patient exercises within a few hours of the ingestion. At the present time, the mainstays of therapy include educating patients and their caregivers to strictly avoid food allergens, to recognize early symptoms of anaphylaxis, and to self-administer injectable epinephrine. However, clinical trials are now under way for the treatment of patients with peanut anaphylaxis using recombinant humanized anti-immunoglobulin E antibody therapy, and novel immunomodulatory therapies are being tested in animal models of peanut-induced anaphylaxis.