A 16-year-old teenager presented with acute severe eye pain and mild epistaxis. The family physician diagnosed an ophthalmologic emergency requiring evaluation. Acute sinusitis was not entertained. Subsequently, ENT evaluation and CT scan confirmed maxillary and anterior ethmoidal sinusitis. This lead to a search for criteria to improve diagnosis of acute sinusitis in the GP setting. Two or more of these symptoms – mucopurulent rhinorrhoea, nasal obstruction/congestion, facial pain/pressure and decreased sense of smell increase its likelihood. Other important issues discussed include differential diagnosis of eyepain associated with epistaxis, potential orbital complications of sinusitis and causes of the quiet, non-red eye.