Objective:This study was conducted to investigate the levels of IL-23 and IL-17 in sera and tumor tissues and to ana-lyze their association with clinico-pathological parameters in patients with colorectal cancer (CRC). Methods:A total of 24 healthy sub-jects and 56 patients with CRC were recruited in this study. Enzyme-linked immunosorbent assay was performed to measure the concen-trations of IL-23 and IL-17 in the sera of CRC patients and healthy controls and in cultured normal tissues and tumor tissues from CRC patients. Results:The levels of serum IL-23 and IL-17 were significantly higher in CRC patients than in healthy controls (P<0.01). The supernatant levels of IL-23 and IL-17 in tumor tissues were significantly higher than in normal tissues (P<0.05). Serum IL-17 level was correlated with tumor location, lymph node metastasis, and TNM stage (P<0.05), whereas serum IL-23 level showed no correlation with all clinico-pathological parameters (P>0.05). Tumor supernatant IL-17 level was correlated with tumor differentiation, lymph node metastasis, and TNM stage (P<0.05), whereas tumor supernatant IL-23 level was correlated only with TNM stage (P<0.05). Conclu-sion:IL-23 and IL-17 may be involved in the immuno-pathogenesis of CRC progression.