Allergen immunotherapy (AIT) is effective in patients with allergic respiratory symptoms related to IgE-mediated sensitization; effectiveness of pharmacological treatment and potential risk/benefit ratio should be assessed before the AIT is started. Effectiveness of AIT has been documented in patients with allergic rhinitis and conjunctivitis, atopic asthma, and Hymenoptera venom allergy. To facilitate qualification of a patient with respiratory symptoms for AIT, we propose to follow four steps algorithm, which includes: fulfillment by a patient of basic criteria (symptomatic, IgE-mediated allergy), assessment of effectiveness probability, chances for preventive effects and lack of contraindications to immunotherapy.