We assessed the contribution of genetic polymorphisms of glutathione S-transferase M1 ( GSTM1), T1 ( GSTT1), and P1 ( GSTP1, Ile105Val) to carotid atherosclerosis in 40 postmenopausal rheumatoid arthritic (RA) women without histories of smoking. We measured mean intima-media thickness (IMT) and plaque of the common carotid arteries by ultrasonography and evaluated relationships among the known risk factors for atherosclerosis, genetic polymorphisms, RA outcomes, and markers of inflammation. Subjects with the GSTT1-0 genotype had greater IMT ( P<0.05). On univariate analysis, carotid IMT was positively associated with age, systolic BP, antihypertensive drug use, and the GSTT1-0 genotype ( P<0.05). When compared to subjects with a double-positive GSTM1/T1 genotype, IMT in those with concurrent lack of the GSTM1 and GSTT1 genes was significantly increased ( P=0.008). This study suggests that the GSTT1-0 genotype might have an interaction with carotid atherosclerosis related to RA in Korean postmenopausal RA women without histories of smoking.