An inadequate selenium level is supposed to be a risk factor for cardiovascular diseases. However little is known about variation of the genes encoding selenium-containing proteins that would confirm the causality in these diseases. The aim of this study was to analyze the relationships between two functional variants of selenoprotein P gene (SEPP1 rs3877899G>A, rs7579G>A) and the occurrence of abdominal aortic aneurysm (AAA) and aortoiliac occlusive disease (AIOD), as well as their metabolic risk factors. In AAA, the rs3877899A allele was associated with higher systolic blood (P < .003) and pulse pressure (P < .003) values (recessive model), and with coexistence of peripheral arterial disease (PAD; carriers: P = .033). The other SEPP1 variants were associated with BMI values and influenced the risk of aortic diseases, depending on body weight. The strongest associations in the case-control analysis was found between the presence of the rs3877899G-rs7579G haplotype and development of AAA in overweight and obese subjects (OR = 1.80, 95%CI = 1.16-2.79, P = .008). The higher BMI values were correlated with lower age of AAA patients and larger size of aneurysm. Our results suggests the potential role of the selenoprotein P in pathogenesis of AAA. Future studies should consider the role of the rs3877899G-rs7579G haplotype as a risk factor for aggressive-growing AAAs.