Background <p>The study aimed to investigate the correlation of carotid plaque and peripheral carotid adipose tissue (PCAT) characteristics with coronary computed tomography-derived fractional flow reserve (CT-FFR) values.</p> Methods <p>Data of 136 patients who underwent head and neck computed tomography angiography (CTA) followed by coronary CTA were retrospectively reviewed. Based on their CT-FFR values, they were divided into CT-FFR ≤ 0.8 and CT-FFR &gt; 0.8 groups. The patients’ baseline data, carotid plaque and PCAT characteristics were collected. Univariate analysis and multivariate logistic regression were employed to identify differences between groups.</p> Results <p>Univariate analysis indicated a statistical differences in carotid plaque thickness, plaque area, plaque load, the carotid plaque Crouse score, minimum plaque density, and net enhancement value of PCAT of patients (<i>P</i> &lt; 0.05). Based on this, multivariate logistic regression analysis demonstrated that carotid plaque thickness (odds ratio (OR) = 0.553; 95% confidence interval (CI) = 0.360–0.847), the carotid plaque Crouse score (OR = 0.653; 95% CI = 0.514–0.830), and net enhancement value of PCAT (OR = 0.820; 95% CI = 0.730–0.919) were independent predictors of the diagnosis of CT-FFR ≤ 0.8. Furthermore, receiver operating characteristic curve analysis showed that the area under the curve of plaque thickness, the carotid plaque Crouse score, and net enhancement value of PCAT for the diagnosis of CT-FFR ≤ 0.8 were 0.816, 0.843, and 0.836, respectively.</p> Conclusion <p>Carotid plaque thickness, the carotid plaque Crouse score, and net enhancement value of PCAT are independent related indicators of CT-FFR ≤ 0.8, which can be simultaneously clarified by head and neck CTA alone, as well as the severity of coronary atherosclerosis.</p>