Our primary goal was to utilize pulmonary arterial stiffness (PAS) to demonstrate the early alterations in the pulmonary vascular area in individuals with prior COVID-19 illness who had not undergone hospitalization. In total, 201 patients with prior COVID-19 infection without hospitalization and 195 healthy, age- and sex-matched individuals without a history of COVID-19 disease were included in this prospective analysis. The PAS value for each patient was calculated by dividing the mean peak pulmonary flow velocity by the pulmonary flow acceleration time. The measured PAS was 10.2 ± 4.11Hz/msec in post-COVID-19 participants and 8.56 ± 1.47Hz/msec in healthy subjects (P < 0.001). Moreover, pulmonary artery acceleration time was significantly lower in patients with a prior history of COVID-19. Multivariable logistic regression analysis revealed that PAS was significantly connected to a prior COVID-19 illness (odds ratio, 1.267; 95% confidence interval, 1.142-1.434; P < 0.001). The optimal cutoff point for detecting a prior COVID-19 disease for PAS was 10.1 (sensitivity, 70.2%; specificity, 87.7%). This might be the first investigation to reveal that patients with a history of COVID-19 had higher PAS values compared to those without COVID-19. The results of the investigation may indicate the need of regular follow up of COVID-19 patients for the development of pulmonary arterial hypertension, especially during the post-COVID-19 interval.