The term compliance simply indicates how much doses of the prescribed medication are taken, whereas the term adherence implies also an agreement between patient and physician about the therapeutic plan, and it is therefore preferred. Adherence is a main problem in all long-term treatments. Thus, it represents a problem also in the case of rhinitis, expecially concerning specific immunotherapy that must be assumed continuously for several years. Many factors can affect the adherence, depending on patient, on treatment itself and on the healthcare context, and all those factors usually interact. The adherence measured in controlled trials is usually good, but this does not reflect what happens in real life, where adherence should be preferably measured. There are few data on the adherence in real life for pharmacological treatments of allergic rhinitis (e.g. nasal steroids or antihistamines), whereas more data are available for specific immunotherapy. In this latter case, in real life, adherence seems to be far from optimal, for both sublingual and subcutaneous immunotherapy, although the recent studies agree on the fact that some interventions (i.e. patients’ education, strict follow-up, regular contacts) could effectively improve the adherence. In this article, the literature concerning the adherence to pharmacological treatments and immunotherapy in allergic rhinitis was searched and reviewed.