Background: Lung atelectasis is a common complication post-cardiac surgery that can affect patient's outcomes significantly. The current study aimed to evaluate the efficacy of transalveolar pressure measurement (PTA) using esophageal manometer as a monitoring parameter during a modified stepwise staircase lung recruitment employing adaptive ventilation mode (AVM) in postcardiac surgery hypoxic patients. Settings and Design: This study was a prospective case series study. Methods: The study was carried out on 62 adult patients who were undergone on-pump cardiac surgeries. After haemodynamic stabilization of the patient in ICU, esophageal manometer catheter had been inserted then a modified stepwise staircase alveolar recruitment maneuver was done with the use of the transalveolar pressure as the main parameter for the monitoring of the effectiveness and safety of the recruitment maneuver. Agreement between parameters was done and weighted kappa, standard error and confidence intervals at 95% (95% CI) were calculated. Results: During the alveolar recruitment maneuver, the PTA Insp detected 96.7% of the patients with alveolar overdistention and the PTA Exp detected 98.3% of the patients with alveolar optimum PEEP. Statistical significant improvement in both hypoxic index and ultrasound lung aeration score from before to after alveolar recruitment. Conclusion: Transalveolar pressure inspiratory and expiratory were accurate monitoring parameters for alveolar overdistention and optimum PEEP detection selectively.