Objective: Recent developments in sinus endoscopy promote the surgical treatment of frontal sinus diseases. Due to limited experience in Draf-III endoscopic surgery in Iran, this study was designed to evaluate Draf-III indications and their correlation with changes in symptom severity two years after surgery. Materials and Methods:In this historical cohort study, patients who had undergone Draf-III surgery in Amir Alam and Emam Khomeini Hospitals in 2012-2013 with any indication were enrolled. Draf-III indications, complaints before surgery, and the Sino-Nasal Outcome Test (SNOT-22) symptom severity score before and after surgery were evaluated. Patients were evaluated two years after surgery, and then, the changes in symptoms severity and correlated factors were evaluated.Results: Thirty-three patients with a mean age of 37.06 years were evaluated. The symptoms severity score. Draf-III indications were fungal sinusitis in 24.2% of patients, frontal osteoma in 9.1%, resistant polyposis in 45.5%, recurrence after previous surgery in 21.2%, frontal mucocele in 27.3%, and pneumatocele in 3%. Decreasing the symptoms severity score were significantly less in patients with fungal sinusitis as a Draf-III indication (14.37 vs 24.2, p=0.001). The changes in symptoms severity score were significantly greater in patients with resistant polyposis (26.4 vs 18.11, p=0.001) and a recurrence after previous surgery (28.29 vs 20.15, p=0.011). There was also a significant correlation between age and symptom release (p=0.042, r=0.367). Conclusion:Resistant polyposis was the most prevalent indication of Draf-III surgery. Draf-III was more useful for patients with resistant polyposis with recurrence after previous surgery and for older patients, but patients with fungal sinusitis as a Draf-III indication had less symptom severity reduction. Other studies with a larger sample size and longer follow-up duration are needed to further evaluate the efficacy of Draf-III in various indications and conditions.