Therapeutic decisions in otorhinolaryngology are based on clinical experience, surgical skills, and scientific evidence. Recently, evidence-based therapies have gained increased attention and importance due to their potential to improve the individual patient's treatment and their potential at the same time to reduce treatment costs. In clinical practice, it is almost impossible to stay ahead of the increasing mass of literature and on the other hand critically assess the presented data. A solid scientific and statistical knowledge as well as a significant amount of spare time are required to detect systematic bias and other errors in study designs, also with respect to assessing whether or not a study should be part of an individual therapeutic decision. Meta-analyses, reviews, and clinical guidelines are, therefore, of increasing importance for evidence-based therapy in clinical practice.This review is an update of the availability of external evidence for the treatment of nasal obstruction and rhinosinusitis. It becomes evident that both groups of diseases differ significantly in the availability of external evidence. Furthermore, it becomes obvious that surgical treatment options are normally based on evidence of significantly lower quality than medical treatment options.