Aim To investigate the correlation of Th17 cells and Th17-associated cytokines with carotid artery intima-media thickness(IMT) in essential hypertensive patients. Methods After carotid ultrasound examination, 206 essential hypertensive patients were categorized into three groups by the tertiles of IMT, namely, high tertile group, middle tertile group and low tertile group. Peripheral blood Th17 cell frequency and serum levels of Th17-associated cytokines interleukin-17(IL-17), interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) were tested and compared in three groups. The correlation between the various factors and carotid IMT was analyzed. Results In high tertile group, middle group and low group, respectively, Th17 cell frequency was 1.45%±0.30%, 1.19%±0.29%, 1.03%±0.28%; IL-17 was 24.03±6.38, 18.85±6.23, 15.84±5.36 ng/L; IL-6 was 87.09±13.65, 75.26±17.21, 68.40±16.15 ng/L; TNF-α was 77.24±14.91, 65.39±17.62, 60.30±17.51 ng/L. Th17 cell frequency, IL-17, IL-6, and TNF-α in high tertile group were higher than those in middle tertile group and low tertile group(P<0.05). Th17 cell frequency, IL-17, and IL-6 in middle tertile group were higher than those in low tertile group(P<0.05). Pearson correlation analysis showed that Th17 cell frequency, IL-17, IL-6, and TNF-α were positively correlated with carotid IMT(P<0.01). Multivariate linear stepwise regression analysis showed that Th17 cell frequency, IL-17, IL-6, and TNF-α were main risk factors for carotid IMT. Conclusion Th17 cell and Th17-associated cytokines are closely related to carotid artery IMT in patient with essential hypertension.