Objective To explore the levels of IL-17 and IL-23 in serum of patients with thyroid-associated ophthalmopathy (TAO) and their clinical significance. Methods Totally 46 TAO patients were enrolled in Huai'an First People's Hospital from January 2014 to October 2016. According to the clinical activity score (CAS), the patients were divided into inactive stage (CAS < 3, 23 patients) and active stage (CAS ≥ 3, 23 patients). Exactly 22 healthy subjects were enrolled in normal control group (NC group). Serum concentration of IL-17 and IL-23 was detected by ELISA, and the correlations between IL-17, IL-23 and CAS were analyzed. Results There was no significant difference in gender and age among the 3 groups (P > 0.05). The CAS score in TAO active group was significantly higher than that in TAO inactive group (P < 0.05). The serum IL-17 levels were (1,268.21 ± 215.03) pg/ ml and (983.52 ± 207.14) pg/ml in active stage and inactive stage of TAO patients, respectively; both of them were higher than that of NC group (582.63 ± 171.39) pg/ml (P < 0.05), and that of TAO activity group was higher than TAO inactive group (P < 0.05). The serum IL-23 levels were (906.83 ± 193.89) pg/ml and (727.93 ± 172.32) pg/ml in active stage and inactive stage of patients, respectively; both of them were higher than that of NC group (278.22 ± 58.61) pg/ml (P < 0.05), and that of TAO activity group was higher than TAO inactive group (P < 0.05). Levels of IL- 17 and IL-23 in patients with TAO were positively correlated with clinical activity score (CAS) (r values were 0.6305 and 0.6892, respectively), and the correlation was statistically significant (P < 0.05). Conclusion IL-17 and IL-23 are highly expressed in the peripheral blood of patients with TAO; and they are positively correlated with CAS of TAO patients. IL-17 and IL-23 may be involved in the occurrence and development of TAO.