The aim of this study was to identify sphenoid sinus dimensions; and distance between columella nasal and sphenoid sinus; and columella nasal and hypophysis in healthy adult subjects using magnetic resonance imaging (MRI) and to evaluate differences between genders and age groups. The MRI results of 300 healthy subjects (192 females; 108 males) aged 18-68 years were studied. The midsagittal and axial images were used for shape of the sphenoid sinus, and the distance measurements of its related adjacent structures on MRI. The mean values of the distance between columella nasal; and columella nasal and hypophysis; and sinus sphenoidalis width were 65.73 +/- 5.22 mm, 87.05 +/- 4.79 mm and 37.67 +/- 8.40 mm in females respectively, whereas the same values were 71.79 +/- 5.06 mm, 94.52 +/- 6.07 mm and 41.95 +/- 9.32 mm in males, respectively. The means of all measurements were lower in healthy female subjects than in healthy males.Additionally, the classification of sphenoid sinus types were determined to be postsellar type (131), sellar type (46), presellar type (14) and conchal type (1) in females, respectively. The same measurement were determined as postsellar type (82), sellar type (23) and presellar type (3) in males, respectively. Differences between sexes and age related changes were observed in the variations of the size, location and shape of sphenoid sinus were observed The observations presented in this report have defined anatomic parameters that need to be taken into consideration for reference data to determine gender discrepancies, age related changes and helpful for radiologists and clinicians to plan safe surgical approach and avoid surgical risks.