Insect stings can generate a range of immune and clinical reactions. Most reactions are local and self-limiting. Allergic reactions to insect stings can occur at all ages, with or without previous stings. Individuals with a history of anaphylaxis carry a significant risk of life-threatening anaphylaxis with future stings. Health-care providers are often unaware of the tremendous clinical benefits of venom immunotherapy for these select patients. Scientific knowledge about the natural history, risk factors, and optimal therapy for insect sting allergies has improved considerably in recent years.