In our study, the Thr40Ala and Arg213Gly polymorphic variants of the EC-SOD gene (SOD ( 3 )) were investigated for associations with atherosclerosis and other related factors in 144 subjects with significant atheroma (having one, two, or three major coronary arteries with >50% obstruction, and/or peripheral artery lesions, and/or carotid artery stenosis demonstrated by angiography and echography) and in 150 subjects with no significant atheroma.