Aim:Fungal rhinosinusitis in patients with chronic sinusal disease study. In the past decades, there has been an increase in fungal infections, and fungal rhinosinusitis (FRS) has been diagnosed more frequently. Knowing the fungal flora, its prevalence and symptomatic presentation in patients with chronic rhinosinusitis (CRS) will allow a better understanding of this disease, permitting a correct diagnosis, and treatment and formulating its prognosis. Study design: clinical retrospective with transversal cohort. Material and Method: 62 patients diagnosed with FRS were selected among 890 cases of CRS undergoing endoscopic surgery. We assessed clinical history otolaryngologic examination with nasal videoendoscopy, CT scan, microbiologic and histopatologic tests. Results: The prevalence of FRS was 6.7% and the fungal type most frequently found was the gender Aspergillus. Fungal ball was found in more than half the cases, and allergic fungal rhinosinusitis (AFRS) in more than one third of the patients. Evolution after endoscopic sinus surgery was more favorable in patients with fungus ball, with a minor number of recurrences. Conclusions: The symptomatic evolution following endoscopic surgery was more favorable in patients with fungal ball, who require a lower number of re-interventions.