We consider that the nasal cavity and the paranasal sinuses cannot be declared completely normal without a normal CT scan. While CT scans are clearly useful in the evaluation of patients with recurrent sinusitis, it is important to emphasize that they should not be employed exclusively for diagnosis. Nasal endoscopy and clinical evaluation still form the basis for the diagnosis of chronic and recurring sinusitis. The CT technique described should be used only to supplement the clinical data obtained during history-taking and the rhinoscopic/endoscopic examination and is essential before functional endoscopic sinus surgery. The complexity of the diagnostic process is simplified to patient benefit when the radiologist and the otolaryngologist form a functional interactive partnership.