The alternative routes for allergen-specific immunotherapy (oral, sublingual, intranasal) have the overall aim of minimizing or avoiding the possible side-effects caused by the injectory route, and of making the treatment more convenient and acceptable for the patients. The clinical efficacy and the safety of the alternative routes have been clearly demonstrated in many controlled studies for the most common inhalant allergens. The oral routes appear particularly suitable for children and patients with unsatisfactory compliance with the injectory route. On the other hand, nasal immunotherapy, because of its peculiar administration technique, requires a careful choice of well-trained adult patients. In conclusion, the good tolerability, safety and socioeconomic benefits strongly support the use of alternative routes as valid therapeutic options for the treatment of respiratory allergy.