Nasal polyps are common, affecting one to four per cent of the population. Their cause, however, remains unknown and it is possible that it is not the same in all patients. They have a clear association with asthma, aspirin sensitivity and cystic fibrosis. Histologically they demonstrate large quantities of extracellular fluid, mast cell degranulation and an infiltrate of inflammatory cells, usually eosinophils. While this appearance would suggest an allergic pathology there is little conclusive evidence to support this in most patients. There is, however, some preliminary evidence to suggest that a local allergic process could be the cause. While allergic fungal sinusitis is a well defined clinical entity with recognized diagnostic criteria the ubiquitous nature of fungal spores makes the role of fungal infection in patients with nasal polyps difficult to determine and currently this remains unclear. Surgical treatment of nasal polyps has declined in recent years as the benefits of medical treatment have become increasingly recognized. There is good evidence to support the use of corticosteroids both as a primary and post-operative treatment in the majority of patients. Other medical treatments require further evaluation before they could be considered a viable alternative to steroids. Assessment of the literature regarding surgical intervention is difficult and there is little evidence on which to base a surgical treatment philosophy. The authors believe that an endoscopic approach using a microdebrider facilitates accurate removal of polyps with preservation of normal anatomy.