Background:Functional Endoscopic Sinus Surgery (FESS) is the removal of tissue obstructing the Osteo Metal Complex. The present study was conducted to determine complications of FESS. Materials & Methods: 82 adult patients of chronic rhino sinusitis selected for FESS of both genders were examined with anterior and posterior rhinoscopy. Lanza Kennedy criteria is used to grade nasal endoscopy findings looking at the presence of secretion, oedema and polyps. The complications were recorded post operatively. Results: Age group 15-24 years had 25 males and 18 females, 25-34 years had 12 and 12 females and 35-45 years had 11 males and 4 females. Common complaints was nasal obstruction in 71, nasal discharge in 15, post nasal drip in 22, headache in 64, halitosis in 10, anosmia & hyposmia in 8 and earache/ ear fullness in 4 patients. Common complications were synechia seen in 45, lower lid ecchymosis in 12, bleeding nose in 10 and orbital subcutaneous emphysema in 4 patients. The difference was significant (P< 0.05). Conclusion: Common complications of FESS were synechia, lower lid ecchymosis, bleeding nose and orbital subcutaneous emphysema.