BACKGROUND Fungal rhinosinusitis (FRS) is an increasingly common pathology in chronic rhinosinusitis and is often diagnosed late. The present study intended at analysing and understanding the clinical, pathological, microbiological, radiological characteristics of the disease in a tertiary hospital in Kerala. METHODS Case records of patients with pathologic or microbiologic diagnosis of FRS were retrospectively studied from January 2015 to January 2021, with reference to their demography, clinical presentation, comorbidities, and imaging features. The treatment aspects were also studied. RESULTS A total of 36 patients with pathological or microbiologic evidence of FRS were studied. There were 58 % cases of allergic FRS, 33 % cases of fungal ball and 8.3 % cases of invasive FRS. 58 % of patients were females, 77 % patients had nasal block as their presenting symptom, and 66 % of patients had duration of symptoms between 1-6 months. In radiological imaging, the maxillary sinus was most commonly involved. Treatment was always surgical removal. Allergic FRS (AFRS) needed prolonged topical steroids and invasive FRS needed systemic antifungals. CONCLUSIONS Our study suggests the importance of early diagnosis of FRS in all chronic rhinosinusitis patients by a high index of clinical suspicion. Tissue samples from the nose and sinuses should be studied for pathology and microbiology in all suspected cases to reach a diagnosis. Radiological imaging can aid in concluding diagnosis. Surgical options, supported by medical management play a vital role in the effective management of the disease. KEY WORDS Fungal rhinosinusitis, Allergic fungal rhinosinusitis, Fungal ball, Invasive fungal rhinosinusitis