Background: Children should be weaned from the ventilator once their clinical condition improves. Extubation failure is associated with poorer clinical outcomes in children. Predictive indicators of successful extubation are needed. This study aims to evaluate the predictive value of ultrasonographic diaphragm imaging could help predict weaning success. Methods: In this prospective, observational study conducted between March and December 2021, children between 1 month and 10 years of age who were mechanically ventilated for more than 48 hours were included. Diaphragm ultrasound (DUS) examinations were performed at the end of 2-hour extubation readiness test (ERT). The end-inspiratory thickness, end-expiratory thickness, diaphragmatic thickening fraction, diaphragmatic excursion, inspiratory slope and expiratory slope were evaluated. Results: Twenty-four (60%) patients were successfully extubated, while 16 (40%) required invasive or non-invasive mechanical ventilation support which were classified as failed extubation group. Three of the sixteen patients in the failed extubation group required re-intubation. Diaphragm thickening fraction was significantly greater in the successful weaning group (55,05 ± 23,75% vs. 30,9 ± 10,38%) (p<0,001). Diaphragm excursion was significantly greater in the SW group (14 ± 4,4 mm vs 11,05 ± 3,25 mm) (p<0,001). DTF and DE were found to have a sensitivity and specificity of 91.67 %, 87.50 %, and 83.33 %, 81.25 %, respectively. Conclusion: Diaphragm ultrasound is a feasible and promising tool to guide physicians during weaning from IMV. Among all DUS measurements, the DE and DTF indexes showed better performance in extubation failure than other diaphragmatic parameters.