Sublingual allergen immunotherapy is a moderate risk procedure. Although the safety data collected so far indicating that it might be relatively safe, it is still exposure to high does of allergens administered in patients’ home, without direct supervision from medical professionals. Therefore, obtaining an informed and written patients informed consent prior the beginning is mandatory. The short chapter deals with legal aspect of sublingual allergen immunotherapy consent. It also delivers examples of the informed consent form to be used in an allergist office.