Chronic periodontitis (CP) and atherosclerotic and aortic aneurysmal vascular diseases (VD) are inflammatory conditions that share a number of predisposing factors. They have a complex genetic heritability and may share genetic risk factors, but a well-defined relationship is still not determined. In addition, distinct genetic patterns of predisposition have been associated with these diseases. Here, we investigated the association of polymorphisms in the IL-1 gene locus with CP in a case–case study analysing VD patients with or without CP. Seventy-four patients with VD of whom 36 had CP were genotyped for single nucleotide polymorphisms in the IL1A -889 (rs1800587), IL1B +3954 (rs1143634) and IL1B at −511 (rs16944) genes and for VNTR polymorphisms in the IL1RN gene. A significantly higher frequency (17%) for allele 1 (four repeats) of the IL1RN VNTR gene was found among the VD patients with CP compared to those without CP. In addition, the frequency of the IL1RN VNTR genotypes 1/1 (4/4 repeats) and 2/2 (2/2 repeats) were significantly higher and lower, respectively, in VD patients with CP. These findings suggest an association of genetic polymorphisms in the IL1-gene locus with risk for CP in patients with VD. The carriage of the risk genotypes, the development and the subsequent influence of CP on systemic health may constitute an additional burden in the pathogenesis of VD. This emphasizes the importance of effective periodontal treatment in patients with VD.