Abstract Background The computed tomography (CT) details of the dimensions of the trachea and the subglottic area are not fully covered in the literature, so it is important to build up a database for the CT measurements of that area. Preoperative details of the trachea are crucial prior to any approach or procedure involving the trachea. So, the aim of this study was to determine the different dimensions of the trachea and subglottic area by computed tomography (CT). Methods From 100 CTs of the trachea acquiring the axial images via the multiplanar reformates for all subjects to get the delicate details measuring the transverse diameter (width) and the anteroposterior diameter (depth) of the trachea and subglottic area. Results The mean tracheal width was 15.5 +_ 2.1 mm (range = 11.5–21.7), and its mean anteroposterior diameter was 16.56 +_ 2.77 mm (range = 11.8–25.1), while the mean width of the subglottic area was 15.1 +_ 1.86 mm (range = 12.3–21.1), and its mean anteroposterior diameter was 17.75 + 2.76 (range = 12.9–25.2). All the dimensions of the trachea and the subglottic area were found significantly smaller in female than males. There was positive correlation between anteroposterior and transverse diameters of the trachea with the subglottic area with more tendency for more subglottic area dimension with increase tracheal dimensions and vice versa. Conclusion The current work updates the CT knowledge about the tracheal and subglottic area dimensions enhancing the surgeons, anesthetist, and radiologists data and orientation of the tracheal dimensions and could aid effective and safe tracheolaryngeal surgery