In the past 30 years, thanks in part to the advance of both endoscopic technology and imaging possibilities, the classification, diagnosis, and management of rhinosinusitis caused by fungi have been better defined. These are basically divided into invasive and non-invasive forms based on the presence or absence of microscopic evidence of fungal hyphae within the tissues. Among the non-invasive fungal sinus diseases, fungus ball has been increasingly reported and large published series have allowed better characterization of the disease and the treatment strategies. Fungus ball of the paranasal sinuses is defined as the non-invasive accumulation of dense fungal concrements in sinusal cavities, most often the maxillary sinus. To describe this entity, confusing or misleading terms such as mycetoma, aspergilloma or aspergillosis would be best avoided. Clinical presentation is non-specific and the diagnosis is usually suspected on imaging studies. Surgical treatment, usually through an endonasal endoscopic approach, is curative. In this paper, we review the clinical, radiological, and pathological presentation of the fungus ball of the paranasal sinuses as well as the surgical management with emphasis on the transnasal endoscopic approach.