RORc2 is the master transcription factor of T helper 17 cells. We aimed to evaluate whether RORc2 genetic polymorphism and serum levels have association with the risk and activity of rheumatoid arthritis (RA). RORC genetic polymorphisms were investigated by real time PCR. Serum RORc2 protein levels were determined by enzyme-linked immunosorbent assay. Protective effects of rs370515 CT, rs370515 CT + TT, rs3828057 CT, rs3828057 CT+TT and rs9826 GG genotypes were detected. The genotype-phenotype analysis showed no significant differences in the disease activity score 28 (DAS 28) under the recessive versus dominant genotypes. RORc2 protein serum levels were significantly higher in RA patients than controls (P= 0.001) and had a positive correlation with DAS-28. In conclusions, RORC genetic polymorphisms correlate with the risk but not activity of RA, whereas RORc2 serum levels have a positive correlation with both risk and activity of RA.