Background: We hypothesized that bedside lung ultrasound (LUS) and echocardiography could be a predictor of postextubation distress by detecting a high lung aeration defect immediately before weaning by evidencing significant lung derecruitment during the spontaneous breathing trial (SBT). Objective: To evaluate the effectiveness of Lung Ultrasound (LUS) and Transthoracic Echocardiography (TTE) in predicting successful weaning of mechanically ventilated patients. Patients and Methods: This study was performed on 50 mechanically ventilated patients in general and respiratory ICU during the period from August 2019 to January 2021, at Bab-Al-Sha'reia University Hospital. Lung ultrasound and echocardiography were determined before and at the end of a 60-min spontaneous breathing trial (SBT) and 4 hrs. after extubation. To quantify lung aeration, a lung ultrasound score was calculated. Results: Forty-five patients had SBT success (90%) and 5 patients experienced SBT failure (10%), From those patients with SBT success, there were 16 patients (35.56%) had post extubation distress, and 29 patients (64.44%) had post extubation success. In patients who successfully passed the SBT, a lung ultrasound score ≤10 at the end of the SBT was highly predictive of postextubation success with a statistically significant difference (p value < 0.001). On the other hand, lung ultrasound score ≥18 at the end of the SBT was highly predictive of postextubation distress with a statistically significant difference (p value < 0.001). We found significant differences in E/A ratio 1.08 ± 0.2 in patients with spontaneous breathing trial success, and 1.6 ± 0.1 in patients with SBT failure with a statistical significant (p-value < 0.001). Conclusion: LUS and TTE during spontaneous breathing trial may accurately predict postextubation distress.