The aim of this prospective anatomical study was to determine the place of the thyroid alar cartilage graft (TAC) in the laryngotracheoplasty in a population of premature and newborn babies. Ninety-eight fresh larynges, collected from autopsies, were included in the study. After measurement of cartilage dimensions and thickness, the potential dimensions of TAC and its widening capacity were calculated for each specimen. The results showed that TAC thickness was similar to the anterior cricoid arch but was significantly less than the posterior cricoid arch. The maximal degree of stenosis which could be normalized by TAC ranged between 47.8 and 74.3%. The height of the TAC allowed a widening, from the level of the glottis to the inferior part of the second tracheal ring in 100% of cases and to the inferior part of the third tracheal ring in more than 70% of cases. In conclusion, the TAC could be used for anterior grafting in laryngotracheoplasty. Its indications should be limited to grade II and a few grade III of the Myer subglottic stenosis classification without glottic or tracheal extension. Moreover, variability of TAC dimensions leads to peroperatively reassess its indication.