Background: the frequency of post extubation stridor (PES) may range between 2–15% in critical children and is a significant cause of reintubation with a higher degree of mortality.The laryngeal US to measure the air column width was described to be a possible method to PES and laryngeal edema. Objectives: We aimed to investigate the reliability of laryngeal ultrasound for the prediction of PES. Patients and Methods: A prospective observational study that was conducted at the PICU of Cairo University Hospital on 50 ventilated children between January 2020 and January 2021. The children underwent laryngeal ultrasound during the first 24 hours of admission and after passing the spontaneous breathing trial and preparing for extubation. Results: the incidence of stridor was 18% and the main risk factors were the longer duration of ventilation and the repeated intubation attempts, the stridor group had a median of 12 days while the non-stridor group had a median of 6 intubation days (p-value = 0.023). The PES had a statistically significant variation in air column width ratio in stridor children compared to the non-stridor group (p- < 0.001). A cut-off point < 0.86 could predict PES with sensitivity of 100% and specificity of 97%. Conclusion: laryngeal air column width ratio is a safe, easy, and reliable method for the prediction of PES in critically ill mechanically ventilated children.