Computerized tomography (CT) offers the gold standard in terms of imaging the extent of disease and the fine detailed anatomy, both pre-requisites to the safe practice of endoscopic sinus surgery. Neither plain X-rays nor magnetic resonance imaging (MRI) offer optimal information in this respect. A variety of protocols minimizing radiation dose to the lens whilst providing high quality images are presented together with a menu of anatomical features that require careful evaluation pre-operatively.