Summary: At present allergic diseases can be effectively managed with numerous therapeutic options. However, all available pharmacotherapeutics work only on the symptoms and fail to provide a long-term effect. As the only causative, disease-modifying treatment, allergen immunotherapy (AIT) is the only option with the potential to “cure” the disease and provide relief even after cessation of treatment. It is currently indicated in allergic asthma, moderate to severe allergic rhinitis with or without conjunctivitis and, under special circumstances, in atopic dermatitis. With several allergen preparations available in both oral and subcutaneous form, it is characterized by wide versatility, cost-effectiveness and safety. Moreover, venom immunotherapy is the single treatment with the potential to effectively reduce the risk of future life-threatening systemic reactions in patients with Hymenoptera venom allergy. Numerous reviews and meta-analyses have confirmed that with accurate patient qualification and safety measures, AIT is efficacious, safe and cost-effective. Several guidelines for allergen immunotherapy qualification and treatment are available, but the recent position paper of the Polish Society of Allergology as well as the recommendations of the European Academy of Allergy and Clinical Immunology seem the most applicable in the Polish healthcare system, for both allergy specialists and primary-care physicians treating allergic patients.