Aim: Increased ratio between the right and left ventricular (RV/LV) diameters =1 is considered an important imaging marker for risk stratification among patients diagnosed with acute pulmonary embolism (PE). Our goal was to assess the prevalence of RV/LV=1 among consecutive patients undergoing computed tomography pulmonary angiography, and to compare the prevalence of RV/LV=1 between patients with and without PE. Methods: Retrospective analysis of consecutive patients who underwent computed tomography pulmonary angiography due to clinical suspicion of PE between January 1, 2014 and December 31, 2014. The axial RV/LV diameters were measured. The prevalence of RV/LV =1 was compared between patients with and without PE and among PE patients, between those with central versus peripheral PE. Results: The final cohort included 862 patients. A total of 142 (16.5%) had PE. RV/LV =1 was found in 553 (64.1%) of all patients, of them in 453 (63%) patients without PE and in 100 (70.4%) patients with PE (P=0.117). On multivariate analysis, PE was not significantly associated with RV/LV =1 (odds ratio [OR]: 1.4; 95% confidence interval [CI]: 0.9-2.1; P=0.102). There was no significant difference in the prevalence of RV/LV =1 among patients with central versus peripheral PE distribution (79.5% vs. 67%, P=0.101). Older age (OR: 1.03; 95% CI: 1.02-1.04; P<0.001) and male gender (OR: 1.51; 95% CI: 1.11-2.03; P=0.008), among all patients, were significantly associated with RV/LV diameter =1. Conclusion: As RV/LV =1 is highly prevalent (64.1%), without a significant difference between those with and without PE, an RV/LV =1 might not represent the cardiac response to the acute PE event, but rather the patient's baseline condition.