Radiographs of the nasopharynx are routinely performed for nasopharyngeal soft tissue changes. The value of lateral neck radiographs in the detection of masses of the nasopharynx has been recognized since the early 1930s. To establish the constitution of a normal amount of nasopharyngeal soft tissue, as viewed on a lateral roentgenogram of the skull, we made various measurements of nasopharyngeal soft tissue thickness on the lateral skull films of 214 Koreans(109 males & 105 females). We recommend measurement of four sagittal diameter of the soft tissue of the nasopharynx, namely, roof thickness ; thickness of the soft tissue that is 2cm from the basion anteriorly perpendicular to basisphenoid, posterior wall thickness ; thickness of the soft tissue along a line which extends from the basion to the posterior edge of the hard palate, C₁-postpharyngeal space ; thickness of the soft tissue from the most anterior portion of the anterior arch of the atlas, C₂-postpharyngeal space ; thickness of the soft tissue from the most prominent point of the body of the axis. The results were as follows : 1) The roof thickness was 11.0±2.1mm in the male and 9.6±2.0mm in the female. The value of the male was greater than that of the female and the normal range was 6mm~16mm in the male and 5mm~14mm in the female. 2) The Posterior wall thickness was 20.5±2.9mm in the male and 19.0±2.7mm in the female. The value of the male was greater than that of the female and the normal range was 14mm~27mm in the male and 13mm~25mm in the female. 3) The C₁-postpharyngeal space was 4.1±1.8mm in the male and 3.8±1.2mm in the female. The value of the male was greater than that of the female and the normal range was 2mm~8mm and 1mm~7mm in the female. 4) The C₂-postpharyngeal space was 3.7±1.3mm in the male and 3.3±1.1mm in the female. The value of the male was also greater than that of the female and the normal range was 1mm~7mm in the male and 1mm~6mm in the female. Generally, as like the previous reports by other authors, the values of males are slightly greater than those of females and the thickness is slightly decreased by aging. The roof thickness is always less than the thickness of the posterior wall and the soft tissue outline is a smooth concave counter. A comparison of our findings with of other authors, shows the overall mean values to be similar.