Catalase (CAT) and peroxisome proliferator activated receptor-gamma2 (PPARgamma2) are important regulators of oxidative stress and inflammation, and may contribute to the development of rheumatoid arthritis (RA). We investigated the association between CAT and PPARgamma2 genotypes and risk and severity of RA using 474 cases and 400 controls. Genotyping for the -262C-->T polymorphism of CAT and the Pro12Ala polymorphism of PPARgamma2 was performed by PCR-RFLP analysis. Severity of RA was assessed by the anatomical stage according to Steinbrocker, and a Korean language version of a Health Assessment Questionnaire (KHAQ). No association was observed between CAT and PPARgamma2 genotypes and risk of RA. Our results suggest that genetic polymorphisms of CAT and PPARgamma2 do not play a significant role in the susceptibility to RA among Koreans.