It has been well known that pulmonary hypertension (PH) caused by congenital heart disease (CHD) leads to reduced flexibility of the small pulmonary arteries, due to hemodynamic changes in the pulmonary circulation and alterations of the vasoactive profile. However, whether CHD-related PH affects the elasticity of the systemic arteries, such as the common carotid artery (CCA), has not been fully investigated. The purpose of this study was to explore the CCA stiffness in patients with CHD-related PH using the radio frequency data technique. Forty patients with CHD were included. They were divided into PH and non-PH (NPH) groups by the right heart catheter-determined or regurgitation velocity-determined mean pulmonary arterial pressure (mPAP). MyLabTwice (Esaote, Genoa, Italy) ultrasound machine equipped with automatic quality intima-media thickness (QIMT) and quality arterial stiffness (QAS) capabilities was used to measure the left common carotid arterial (CCA) intima-media thickness and arterial stiffness parameters. The results have shown that the left CCA internal diameter, pulse wave velocity, arterial wall tension, and local diastolic pressure were increased in the CHD-related PH group compared with the CHD-related NPH group (all P<0.05). The left CCA internal diameter negatively and significantly correlated with the mean PAP. Common carotid artery diameter and stiffness increase in patients with CHD-related pulmonary hypertension. QIMT and QAS ultrasound techniques may provide a comprehensive assessment of the CCA remodeling.