Chewing Khat is considered as a major deep-rooted sociocultural habit in Yemen. This custom has been causing various health problems. Using Doppler ultrasonography, this study assessed the changes that occurred in bilateral carotid arteries’ flow velocities and Doppler indices in Yemenis who regularly chewed Khat for years. Convenient sampling was conducted from August 2017 to August 2018 for 384 participants of whom 179 were excluded and the sample size became 205 participants including 108 (52.7%) Khat chewers and 97 (47.3%) non-Khat chewers. The mean age of the sample was 28.29 ± 7.0 years. In all cases, the carotid Doppler ultrasound scanning protocol, based on the standards of American Institute of Ultrasound in Medicine, was performed to measure carotid Doppler velocities and indices, in addition to internal carotid flow volume. The Khat chewing information of participants was obtained by a standardized questionnaire, and SPSS was used for result analysis. There were differences in systolic velocities between Khat chewers and non-chewers with lower values for the chewers, and they were significant in the right common carotid artery and in the internal carotid artery. The carotid Doppler indices, except the right internal carotid artery, were significantly decreased, and the Right internal carotid artery blood flow volume was significantly increased among Khat chewers compared to that of non-chewers. Moreover among Khat chewers, Doppler indices and most of the peak systolic velocities had a significantly negative correlation with the Khat chewing period. Therefore, this study may provide an interpretation of the high prevalence of hemorrhagic stroke among Yemeni population in their middle age, and suggest the mechanism that may cause this type of stroke. More studies are recommended to confirm this finding using the transcranial Doppler technique.