Aim: To investigate the effects and the severity of pulmonary embolism on the cardiovascular system and lung parenchyma. Material and Method: Pulmonary artery (PA) obstruction index ratios were calculated, and cardiovascular and pleuroparenchymal changes were retrospectively assessed in 180 patients with a prediagnosis of PE using computerized tomography pulmonary angiography (CTPA). Results: Main PA, right PA, and mean superior vena cava (VCS) diameters, right (RV) and left ventricle (LV) short diameters, and RV/LV ratios in patients with PE were increased (p<0.001, p=0.004, p=0.007, p=0.01, p=0.001, respectively) and correlated with the obstruction index ratio (OIR). Also, the convexity of the interventricular septum, VCI, and vena azygos reflux frequency were increased with PE (p<0.001, p=0.001, p=0.001) and with massive PE (p<0.001, p=0.003, p<0.001). It was determined that the frequency of the presence of wedge-shaped opacities and vein mark findings was increased in patients with PE (p<0.001, p<0.001); however, it was found less frequently in patients with massive PE when compared to the submassive patients (p=0.002, p=0.014). The presence of atelectasis was not different between patients with and without PE; consolidation, ground glass appearance, oligemia frequency, and the average scores were increased in the patients with PE (p=0.02, p<0.001, p=0.001), and there was a positive correlation between the oligemia score and OIR (r=0.202, p=0.027). Pleural effusion was infrequent with PE. Discussion: CTPA is a rapid and reliable method for the determination of the severity of PE, affected vascular structures and lung regions, and for the assessment of right heart function.