Background: Optimization of intraoperative mechanical ventilation can decrease the incidence of pulmonary postoperative complications and improve outcome in obese patients. Objective: To study the effect of different modes of ventilation [volume control, pressure control and pressure control volume-guaranteed] with pneumoperitoneum on pulmonary mechanics and cardiovascular parameters and the incidence of post-operative pulmonary complications. Patients and methods: This study was carried out on 90 patients subjected to laparoscopic sleeve gastrectomy operation at Al-Azhar University Hospitals from March 2020 till October 2020. The participants were divided into 3 equal groups according to mode of mechanical ventilation: Group Ⅰ: Volume control ventilation, Group Ⅱ: Pressure control ventilation and Group Ⅲ: Pressure control volume-guaranteed ventilation. Intraoperative parameters (SaPo2, EtCO2, PaCO2, Ppeak, Pplateau, dynamic compliance, exhaled tidal volume, oxygenation index, heart rate, mean ABP) were measured before pneumoperitoneum, 15 minutes after pneumoperitoneum and 5 minutes after desufflation. Postoperative parameters (SaPo2 and PaO2/FiO2 ratio) were measured for 24 hours, every hour during the first six hours, then every 2 hours during the next six hours and every 4 hours during the next 12 hours. Results: Volume control group was the highest group in peak airway pressure, and the lowest group in dynamic compliance before and after pneumoperitoneum and after desufflation. The difference between volume control group and the other two groups [pressure control group, pressure control volume-guaranteed group] was statistically significant. Conclusion: Pressure control ventilation and pressure control volume-guaranteed was lower in peak airway pressure and higher in dynamic compliance compared to volume control ventilation.