The present review summarizes the literature-acquired knowledge as well as author's own experience in conducting aero-allergen immunotherapy, particularly in subcutaneous route of administration (SCIT) of all modalities of respiratory allergy disease from allergic rhinosinusitis, bronchial asthma to united airway disease. Because of the better adherence resulting in appropriate efficacy in connection with satisfactory safety, the author favours conventional schedules of subcutaneous route of therapeutic intervention. Given the lack of specific biomarker in monitoring treatment course, the main control mechanism of efficacy is the evaluation of quality of life using simple evaluation scale as visual analogue scale or standardized respiratory allergy questionnaires. The future of allergen immunotherapy should be focused on new routes of allergen administration (e.g. oral, epicutaneous, intradermal, intralymphatic) and on the searching potential biomarkers which could be objectively measured and easily accessible from body fluids (blood, nasal secretion, sputum). The combination of estimated biomarkers obtained from biological samples in conjunction with evaluation of quality of life could lead to the generation of the overall satisfactory monitoring protocol.