The prevalence of allergic diseases has been increasing over the past 50 years, leading to social and economic consequences. Immunotherapy is the only disease-modifying therapy available for allergic diseases, with durable long-term benefits. Immunotherapy is primarily available in two forms : 1) subcutaneous injections or 2) sublingual tablets/drops. The latter offers the advantage of being managed by the patient himself, requires no injections and has a far lower risk of severe systemic adverse events. In Switzerland, the use of sublingual immunotherapy is still scarce. This article reviews the indications, the administration technics and the contraindications to sublingual immunotherapy.