The combination of nasal polyposis, crust formation, and sinus cultures yielding Aspergillus was first noted in 1976 by Safirstein, who observed the clinical similarity that this constellation of findings shared with allergic bronchopulmonary aspergillosis (ABPA). Eventually, this disease came to be known as allergic fungal rhinosinusitis (AFRS). As clinical evidence of AFRS accumulated, controversy regarding its etiology, pathogenesis, natural history, and appropriate treatment naturally emerged. Despite past and current efforts, many of these controversies remain incompletely resolved, but continuing clinical study has illuminated some aspects of the disease and has led to an improved understanding of AFRS and its treatment. In this article, we review current data and theories regarding the pathophysiology and clinical presentation of AFRS, as well as the roles of various surgical and nonsurgical forms of therapy.