Background: Prone position is one of the challenging and widely used surgical positions with high rates of complications. The applied position and selected ventilation parameters during the operation are known to influence the pulmonary mechanics. Objective: This study was conducted to compare two modes of ventilation; volume controlled and pressurecontrolled ventilation and their effect on improvement of respiratory dynamics. Patients and Methods: This prospective randomized controlled study included a total of 60 patients who had posterior lumbar spine surgery in prone position, attending at Department of Anesthesiology and Surgical ICU, Aswan University Hospital, Egypt. This study was conducted between June 1, 2017 to December 13, 2018. Patients were randomly divided between two groups, 30 patients each; Group (I): were received VCV mode and Group (II): were received PCV mode. Then study parameters were recorded intraoperative and postoperative in the two groups of ventilation modes. The study parameters which were recorded: Peak inspiratory pressure (Ppeak), Plateau pressure (Pplateau), dynamic compliance (Cdyn), ETCO2, Tidal volume (VT), respiratory rate (RR). Results: As regarding Ppeak and Pplat, they were statistically significant lower in PCV group than VCV group at both supine and prone positions. As regarding Cdyn, it was statistically significant higher in PCV group than VCV group at both supine and prone positions. Arterial oxygen tension (PaO2) was significantly higher in PCV group intraoperative in prone position and postoperative. Conclusions: Compared with VCV, PCV is better regarding the respiratory dynamics including lower Ppeak and Pplat. It has also higher Cdyn and oxygenation. PCV it is more suitable for general anesthesia of posterior lumbar spine surgery patients in prone position.