Background: Accurate risk stratification is the most important step in the management of patients with acute pulmonary thromboembolism (PTE). Pulmonary embolism severity index (PESI) is a clinical tool for PTE risk stratification. CHA 2 DS 2 -VASc score, a risk assessment tool in patients with atrial fibrillation, is recently considered for acute PTE. The presence of right ventricular (RV) dysfunction in imaging is more efficient in acute PTE risk evaluation. Hypothesis: This study aims to evaluate the association between CHA 2 DS 2 -VASc and PESI score and each of them with RV dysfunction on computed tomography pulmonary angiography (CTPA). Methods: One hundred eighteen patients with a definite diagnosis of PTE were entered. The CHA 2 DS 2 -VASc and PESI scores were calculated for all of them. RV dysfunction including an increase in RV to left ventricular diameter ratio, interventricular septal bowing, and reflux of contrast medium into the inferior vena cava was examined by CTPA. Results: PESI and CHA 2 DS 2 -VASc scores were significantly associated with RV dysfunction. In addition, different classes of PESI scores were correlated with RV dysfunction. Moreover, this study showed that the CHA 2 DS 2 -VASc score and PESI score had a positive correlation. The area under the curve value for the CHA 2 DS 2 -VASc score was 0.625 with 61.54% sensitivity and 60.0% specificity for predicting RV dysfunction while for PESI score was 0.635 with 66.7% sensitivity and 60.0% specificity. Conclusion: This study showed that not only CHA 2 DS 2 -VASc and PESI scores are positively correlated, but they are both associated with RV dysfunction diagnosed by CTPA. CHA 2 DS 2 -VASc and PESI scores are able to predict RV dysfunction.