A case is presented with irreversible blindness in one eye and restriction of the infratemporal visual field in the other eye, due to electrocoagulation performed for delayed bleeding after functional endoscopic sinus surgery (FESS). Although blindness due to rhinosurgery is a well-known, but rare complication, a review of the recent literature did not reveal a similar incident. The use of electrocoagulation especially under conditions of poor visualization, that may be the case in post-operative bleeding following (endoscopic) sinus surgery, is strongly discouraged.