Aim: Paranasal sinuses are the anatomic regions that are frequently affected by allergic diseases and infections, thus it is substantial to comprehend the morphological structure of these regions for surgery. The aim of our study is to obtain stereological evaluation of frontal sinus volumes of female and male individuals by using computerized tomography (CT). Material and Method: This study assessed the CT images of 140 cases (70 male, 70 female) were at the age of 20 to 60 years and didn't have a disease of frontal sinus. Frontal sinus volumes were calculated stereologically on coronal plane sections by using planimetric method via Cavalieri principle. Results: When the data of male and female individuals were compared statistically; it was observed that frontal sinus volumes of men were larger. Average frontal sinus volume of women was 4,04 +/- 1,84 cm(3) and it was 7,02 +/- 2,78 cm(3) for men. Discussion: Significant advancement was obtained for paranasal sinus imaging by the use of CT, magnetic resonance imaging and three dimensional imaging techniques. In our study, frontal sinus volumes of adult individuals were measured by using planimetry method and it was detected significantly larger in men. Since frontal sinus is one of the paranasal sinuses that reveal asymmetrical development, it is clinically important to seek out its volume. In conclusion; we think that determination of the frontal sinus volume will make a major contribution to physicians for inflammatory sinus diseases, frontal sinus traumas and endoscopic sinus surgery.