CT is accepted as the gold standard for pathological-anatomical evaluation of paranasal sinus disease, CT is especially considered an obligatory part of planning surgical procedures. Indications for paranasal sinus CT include trauma, malignant disease, and chronic sinusitis, which accounts for the major part of examinations. Due to the benign character of the disease and the relatively moderate age of the patients involved, the radiation dose of paranasal sinus CT plays an important role. The use of a low-dose spiral CT technique and the reformation of coronal images out of the axial CT data instead of an additional direct coronal scan allow the effective dose of paranasal sinus CT to be reduced to the order of a chest radiogram. MRI is the preferred imaging modality in malignant disease or complications of inflammatory sinus disease that extend beyond the limits of the paranasal sinuses. The clinical value of other imaging modalities, including plain film radiography, ultrasound, or scintigraphy, is limited to special indications.