The association between oral and systemic health has highlighted the importance of periodontal health and treatment, with the consequence that dental assessment and attention to oral hygiene have assumed an increasingly important part in the clinical management of patients with diabetes mellitus and rheumatoid arthritis. The aim of this work was to assess genotype frequencies in polymorphisms of genes of IL-1 alpha-889 and IL-1 beta-511 in a case-controlled study population of patients affected by periodontal disease and rheumatoid arthritis or diabetes mellitus.