Chronic Rhinosinusitis is a common disorder, and its prevalence vary from 1-20% globally. The incidence of fungal sinusitis has increased to such extent in recent years that fungal infection is a common diagnosis in patients with Chronic Rhinosinusitis. The objectives of this current research were objectives of estimating the prevalence of Fungal aetiology in chronic sinusitis patients and their drug sensitivity pattern with common antifungal drugs. A total of 61 Cases present with Chronic Rhinosinusitis (CRS), visited in a tertiary care hospital based in Central Delhi, were included in our study. Excision of sinus tissue, including polyps and masses, were collected in the operation theatre during Functional Endoscopic Sinus Surgery (FESS) procedure in a sterile manner. All the tissues brought in sterile normal saline were processed for bacteriological and mycological examination. Tissues, obtained in 10% formalin were processed for histopathological and cytological analysis. A total of 14 (22.9%) cases of Chronic Rhinosinusitis were affected by fungal etiologies. By E test, the MIC range for isolates of Rhizopus arrhizus after 24 hr of incubation was 1-2 μg/mL, and the mean was 1.5 μg/Ml. Similarly, the MIC range for isolates of Aspergillus flavus after 48 hr of incubation was 0.5-16 μg/mL, and the mean was 4.09μg/mL. By the M38-A broth dilution method, the MIC range for the isolates of Rhizopus arrhizus after 24 hr of incubation was 0.5-2 μg/mL, and the mean was 1.25 μg/ml. Similarly, the MIC range for isolates of Aspergillus flavus after 48 hr of incubation was 0.5-4 μg/mL, and the mean was 1.95 μg/mL.