Interleukin-17F (IL-17F) is a novel proinflammatory cytokine. IL-17F gene is an excellent candidate for chronic inflammatory disease. We investigated the association between rheumatoid arthritis (RA) and His161Arg (7488A/G; rs763780) and Glu126Gly (7383A/G; rs2397084) polymorphism of IL-17F gene. The gene polymorphisms in 220 Polish patients with RA and 106 healthy subjects were amplified by polymerase chain reaction with restriction endonuclease mapping. Overall, the polymorphisms of the IL-17F gene were not correlated with susceptibility to RA in Polish population. However, the IL-17F His161Arg variant was associated with parameters of disease activity, such as number of tender joints, HAQ score or DAS-28-CRP. Moreover, our findings have shown that Glu126Gly IL-17F gene polymorphism may be correlated with longer disease duration in patients with RA. Our results for the first time showed the relationship between IL-17F gene polymorphisms and severity of RA.