en پژوهشی اصيل Original Research <strong>Aims:&nbsp;</strong>Sinusitis is the inflammation of the nasal cavity, and Paranasal sinuses occur by pathogen agents such as bacteria, viruses, fungi, or other allergens. This study was aimed to determine the prevalence of positive fungal cultures in patients with chronic sinusitis undergoing functional endoscopic sinus surgery.&nbsp;<br> <strong>Materials & Methods:</strong>&nbsp;This experimental study was carried out on 60 patients with chronic sinusitis in 2019. After anesthesia in the operating room, the ENT specialist evacuated the sinuses of patients with chronic sinusitis undergoing sinus endoscopic surgery. After sampling of evacuated sinus tissue of eligible patients and transfer to mycology laboratory, fungal elements were identified using direct smear and culture of the sample on sub-dextrose agar medium. The patient&#39;s profiles were recorded. Data were analyzed using SPSS 21 software by the descriptive statistic.<br> <strong>Findings:</strong>&nbsp;36 of selected patients with chronic sinusitis were male (60%), and 24 were female (40%) with a mean age of 38.4&plusmn;11.5 years. Two&nbsp;<em>Candida parapsilosis</em>&nbsp;(3.3%), one&nbsp;<em>Aspergillus flavus</em>&nbsp;(1.7%), and one&nbsp;<em>Aspergillus niger</em>&nbsp;(1.7%) were detected. Therefore, the prevalence of positive fungal cultures in patients with chronic sinusitis undergoing endoscopic sinus surgery was 6.7% in Yasuj, southwest of Iran, in 2019.<br> <strong>Conclusion:</strong>&nbsp;The prevalence of fungal sinusitis is low in patients with chronic sinusitis in Yasuj due to the location of Yasuj in a mountainous region with a cold and dry climate.<br> <span dir="RTL"></span> Sinusitis,Fungi,Prevalence, 151 155 http://jccs.yums.ac.ir/browse.php?a_code=A-10-138-1&slc_lang=en&sid=1 D. Razmjoue 10031947532846004853 10031947532846004853 No Department of Basic Sciences, School of Medicine, Yasuj University of Medical Sciences, Yasuj, Iran S. S. Khoramrooz 10031947532846004854 10031947532846004854 No Department of Microbiology, School of Medicine, Yasuj University of Medical Sciences, Yasuj, Iran M. Jafari Lagharaki 10031947532846004855 10031947532846004855 No Student Research Committee, Yasuj University of Medical Sciences, Yasuj, Iran S. Jafari Lagharaki 10031947532846004856 10031947532846004856 No Student Research Committee, Yasuj University of Medical Sciences, Yasuj, Iran S. Nooripour Sisakht 10031947532846004857 10031947532846004857 No Department of Microbiology, School of Medicine, Yasuj University of Medical Sciences, Yasuj, Iran M. Zoladl 10031947532846004858 10031947532846004858 No Social Determinants of Health Research Center, Yasuj University of Medical Sciences, Yasuj, Iran Gh.A. Sabz 10031947532846004859 10031947532846004859 Yes Department of Otorhinolaryngology, Head and Neck Surgery, School of Medicine, Yasuj University of Medical Sciences, Yasuj, Iran