A nasoendoscopic examination, may be performed to access the drainage pathways of the sinuses.

The nasoendoscope is a small tubular flexible scope that is introduced into the nose to visualise the nasal passages. It is not a painful procedure but some patients may experience a little discomfort. An examination of the nasal passages will also reveal the presence of any purulent nasal discharge.

In cases of persistent sinusitis, a specimen of the discharge may be taken for culture to identify the bacteria and help in the selection of antibiotics.

A computed tomographic scan (CT scan) may also be done to show any anatomical abnormalities that may lead to recurrent or prolonged episodes of sinusitis.