The lateral neck film is a useful guide in evaluating the bony and soft tissue relationships of the neck. The X-ray films of the neck lateral view were studied on normal human adults of 60 males and 38 females for the interpretation of the soft tissue. The regions evaluated were retropharyngeal, postcricoid, pre-6th cervical vertebra and posttracheal soft tissues. Results are as follows : 1. Normal values of the retropharyngeal soft tissue thickness in the hypopharynx were 4.9±1.2mm in male and 4.7±1.0mm in female. 2. Normal values of the postcricoid soft tissue thickness were 5.8±1.4mm in male and 5.6±1.4mm in female. 3. Normal values of the posttracheal soft tissue thickness were 12.8±1.9mm in male and 10.3±1.9mm in female. 4. The ratio between the A-P diameter of the 4th cervical vertebra and the retropharyngeal soft tissue thickness was 0.31 : 1 in male and 0.30 : 1 in female. 5. The ratio between the posttrachecal soft tissue thickness and the inner diameter of the trachea was 0.75 : 1 in male and 0.86 : 1 in female.