Purpose: The purpose of this study is to discover factors that determine mortality in patients with invasive fungal rhinosinusitis.Methods: This retrospective study included 17 patients diagnosed with invasive fungal rhinosinusitis and who had undergone treatment in our department, including both surgical and medical management between January 2020 and October 2020. There were four male patients and 13 female patients whose mean age was 46 ± 15.67 years, ranging from 20 to 70 years. All the patients were immune-compromised because of diabetes mellitus. We studied the factors affecting the mortality of patients affected with this disease; it included the extent of disease (paranasal sinus, palatal, orbital, or intracranial involvement), serum glucose level (SGL), and C-reactive protein (CRP) levels.Results: Only one patient had paranasal sinus involvement alone, but the patient became disease-free after treatment. The disease-specific mortality rate was two (33.3%) of six patients with palatal involvement and four (50%) of eight patients with intracranial involvement where four patients did not have disease control at the time of discharge and did not follow up. The death rate in orbital involvement was 20% (three of 15 patients) and five patients with intra-orbital involvement left the hospital against medical advice.The analysis of data demonstrated that only intracranial (p = 0.01) involvement in addition to the nasal cavity and paranasal sinus involvement had a statistically significant effect on survival rate unlike intra-orbital (p = 0.510) and palatal involvement (p = 0.171).Conclusion: Early endoscopic nasal inspection, diagnosis, and treatment are critical for disease-specific mortality in invasive fungal rhinosinusitis since orbital or cerebral involvement is linked to a poor prognosis. Patients who come with uncontrolled diabetes and ophthalmological and palatal involvement with positive findings on nasal examination should necessitate urgent histopathological and radiological workup.