Two cases of orbital complications secondary to functional endoscopic sinus surgery are presented. One case was complicated in the immediate post-operative period with an orbital haematoma, which required urgent decompression using lateral canthotomy. The second case had presented an acute orbital haemorrhage during functional endoscopic sinus surgery, which required the same surgical procedure. These cases demonstrate that lateral canthotomy constitutes a safe and fast surgical procedure to decrease the intraorbital pressure.