Allergic fungal rhinosinusitis (AFRS) is a distinct type of chronic rhinosinusitis that is relatively new, often misdiagnosed, and incompletely understood. It presents with characteristic clinical, radiographic, and histopathologic findings. The condition should be considered in patients with symptoms of chronic rhinosinusitis resistant to conventional medical therapy. Clinical features, nasal examination, imaging, and laboratory studies are utilised to diagnose AFRS. Mucormycosis is a severe fungal infection known by many researchers as “the most acutely fatal fungal infection”. Though it is mostly harmless in immunocompetent individuals, its manifestations are deadly in the immunocompromised, including people with poorly controlled diabetes, haematological malignancies, and those on steroid or other immunosuppressant drugs. The treatment for mucormycosis needs to be vigorous due to its rapid spread. Other forms of fungal maxillary rhinosinusitis include the presence of a fungal ball in the maxillary sinus and chronic invasive fungal sinusitis. The treatment for a fungal ball is surgical excision, whereas the management of chronic invasive fungal sinusitis includes both surgical debridement and antifungal therapy.