Background: Fungal Rhinosinusitis is one of the common diseases affecting the Nose and Paranasal Sinuses. Various fungi cause the disease. These infections are termed as invasive Fungal Infections, when they occur in immunologically compromised individuals, and Diabetics. Objective: To evaluate the use of diagnostic criteria to confirm the fungal rhinosinusitis disease with radiological, pathological and microbiological investigations and their management. Materials and Methods: A prospective observation study has been conducted at, in which 21 patients presenting to the Ear, Nose and Throat (ENT) department of our institution with clinical features of fungal sinusitis. After thorough clinical examination, the patients underwent investigations including hematological tests, radiological tests, diagnostic nasal endoscopy, histopathological examination and microbiological examination. Clinical examination including complete ENT & Head and Neck examination and cranial nerves examination was done to all the 21 patients included in the study. The data collected was imported into excel sheet (Microsoft Excel) for further evaluation in obtaining the results. The frequencies of distribution of various variables of the study were represented in the form of tables. Results: 19 patients presented with nasal obstruction, 18 with nasal discharge, 14 with sneezing, 8 with headache, 11 with anosmia, 8 with nasal allergy, 9 with asthma, 7 with Diabetes mellitus, and 7 with previous history of nasal surgery. On clinical examination, polyps were found in 16 patients. Conclusion: Post-operative use of Systemic and Local Steroids, Antihistamines, Decongestants, Regular nasal douching and Anti-fungal antibiotics wherever necessary, helps in early healing of the cavities and also reduces recurrence. Postoperative regular follow up for endoscopic suction clearance of the debris, crusts, and removal of granulation tissue, helps in identifying early recurrence and gives the surgeon to plan further treatment.