Background: Pulmonary thromboembolism (PTE) is a significant contributing factor to vascular diseases.This study aimed to determine the prevalence of pulmonary thromboembolism and its predisposing factors in patients with COVID-19. Methods: This cross-sectional study included 284 patients with COVID-19 who were admitted to Nemazee Teaching Hospital (Shiraz, Iran) between June and August 2021. All patients were diagnosed with COVID-19 by a physician based on clinical symptoms or positive polymerase chain reaction (PCR) test results. The collected data included demographic data and laboratory findings. Data were analyzed using the SPSS software. P ≤0.05 was considered statistically significant. Results: There was a significant difference in the mean age between the PTE group and non-PTE group (P=0.037). Moreover, the PTE group had a significantly higher prevalence of hypertension (36.7% vs. 21.8%, P=0.019), myocardial infarction (4.5% vs. 0%, P=0.006), and stroke (23.9% vs. 4.9%, P =0.0001). Direct bilirubin (P =0.03) and albumin (P =0.04) levels significantly differed between the PTE and non-PTE groups. Notably, there was a significant difference in the partial thromboplastin time (P =0.04) between the PTE and non-PTE groups. A regression analysis indicated that age (OR, 1.02; 95% CI, 1.00‒1.004; P =0.005), blood pressure (OR, 2.07; 95% CI, 1.12‒3.85; P=0.02), heart attack (OR, 1.02; 95% CI, 1.28‒6.06; P =0.009), and albumin level (OR, 0.39; 95% CI, 0.16‒0.97; P =0.04) were all independent predictors of PTE development. Conclusion Regression analysis revealed that age, blood pressure, heart attack, and albumin levels were independent predictors of PTE.