Insect sting allergy has served as an excellent model for the allergic process over the past century. In particular, during the last 30 years, a new form of diagnostic testing and treatment with venom has been one of the great success stories in the entire field of allergy. VIT (venom immunotherapy) reduces the risk of recurrent life-threatening reactions from about 60% to less than 2%. Progress and further questions continue with a search for a definitive diagnostic test that more accurately predicts which patients are at risk for future reactions, and defines which patients can stop VIT and which ones need to continue treatment.