This is a report of a case with unilateral cavernous sinus thrombosis due to ipsilateral ethmoid sinusitis.

A 10 year old female was admitted in our hospital with severe headache, purulent postnasal discharge, right eye proptosis and third cranial nerve palsy in the same eye. She had history of viral upper respiratory tract infection and then acute otitis media which did not improve with routine medications. Head imaging showed ethmoid sinusitis and cavernous sinus thrombosis. Clinical manifestation was subsided after thirty days aggressive antimicrobial and anticoagulant therapy.

Ethmoid sinusitis can cause cavernous sinus thrombosis. Appropriate management by antibiotic and anticoagulant therapy can prevent neurologic complications and death