Non-allergic perennial rhinitis is a common disease occurring with the same frequency as perennial allergic rhinitis. It has long been a misunderstood clinical entity and this fact is reflected in the variety of names it has been given in the past. The understanding of the disease is still very incomplete such that it still remains a diagnosis of exclusion. Non-allergic perennial rhinitis usually responds well to medical treatment. Surgical management is reserved for those subjects who fail to respond satisfactorily to such measures and is particularly effective at treating refractory nasal obstruction. The following review discusses the classification, aetiology and treatment of this complex and perplexing condition.