OBJECTIVE The aim of the paper was to perform a 64-slice CT evaluation of the main anatomic variants of paranasal sinuses. METHODS From April 2005 to January 2006, 100 patients were chosen among all those that had undergone a paranasal sinuses CT examination. They were 45 women and 55 men, all aged between 18 and 70 years, mean age 46 years; they were all caucasian. This research has been conducted using a 64-slice Siemens Somatom Volume-Zoom multidetector Spiral CT. Para-nasal sinuses CT examination has been performed through a thin axial acquisition; the patient was lying on his back and the images were processed with multiplanar reconstruction (MPR). The anatomic variants considered in this study are: concha bullosa, Haller cells, uncinate process abnormalities, agger nasi cells, ethmoidal bulla, Onodi cell, middle turbinate curvature abnormalities. RESULTS In this research it has been noticed that 29% of patients are affected by concha bullosa, 5% by Haller cells and again 5% by uncinate process abnormalities; 52% are affected by agger nasi cells, 15% by ethmoidal bulla, 9% by Onodi cell and 11% by middle turbinate curvature abnormalities. CONCLUSIONS By using a 64-slice CT you can get a better quality of images in terms of spatial and temporal resolution. Osteomeatal complex structures are often featured by many anatomic variants. The most of the time, percentages are the same as recent researches have shown.